JP2024042695A - resin composition - Google Patents

Abstract

The present invention provides a resin composition with low melt viscosity that can give a cured product with high relative magnetic permeability and low magnetic loss. The present invention provides a resin composition containing (A) an Fe-Ni-Si-Cr alloy magnetic powder and (B) a thermosetting resin, in which the Cr content of component (A) is 0.1% by mass or more and 6% by mass or less relative to 100% by mass of component (A). [Selected Figure] None

Description

The present invention relates to a resin composition, and a cured product, magnetic paste, resin sheet, circuit board, and inductor board using the resin composition.

A cured product obtained by curing a resin composition containing magnetic powder is sometimes used as a core material of an inductor component. FeNi alloy powder was sometimes used as the magnetic powder (Patent Document 1).

JP 2018-178254 A

Conventionally, it has been common to mount an independent inductor component on the substrate of a semiconductor device. However, in recent years, a method has been used in which a coil is formed using a conductor pattern on a substrate and an inductor element is provided inside the substrate. In order to further improve the performance of inductor elements used in such applications, it is required to further improve the magnetic properties of the core material. Furthermore, when there is a hole in the substrate of a semiconductor device, the hole may be filled with a resin composition containing magnetic powder. In this case, the resin composition is required to have a low melt viscosity.

The present invention was created in view of the above-mentioned problems, and provides a resin composition with low melt viscosity that can yield a cured product with high relative magnetic permeability and low magnetic loss; a cured product of the above-mentioned resin composition. An object of the present invention is to provide a magnetic paste and a resin sheet containing the above resin composition; and a circuit board and an inductor board containing a cured product of the above resin composition.

The inventors of the present invention have made extensive studies to solve the above problems. As a result, the present inventor found that a resin composition containing a combination of (A) Fe-Ni-Si-Cr alloy magnetic powder containing specific amounts of Si and Cr and (B) thermosetting resin, The inventors have discovered that the above-mentioned problems can be solved, and have completed the present invention.

That is, the present invention includes the following.
[1] A resin composition comprising (A) Fe-Ni-Si-Cr alloy magnetic powder, and (B) a thermosetting resin,
A resin composition in which the content of Cr contained in component (A) is 0.1% by mass or more and 6% by mass or less based on 100% by mass of component (A).
[2] The resin composition according to [1], further comprising (C) magnetic powder other than the Fe-Ni-Si-Cr alloy magnetic powder.
[3] The resin composition according to "2", wherein the component (C) contains ferrite magnetic powder.
[4] The resin composition according to [2] or [3], wherein the component (C) contains ferrite magnetic powder containing at least one element selected from the group consisting of Mn, Zn, Ni, and Cu. thing.
[5] The resin composition according to any one of [2] to [4], wherein component (C) has a smaller average particle size than component (A).
[6] The resin composition according to any one of [1] to [5], wherein the (B) component contains (B-1) an epoxy resin.
[7] The resin composition according to any one of [1] to [6], wherein component (B) contains (B-2) a curing agent.
[8] The resin composition according to any one of [1] to [7], further comprising (E) a dispersant.
[9] The resin composition according to any one of [1] to [8], further comprising (F) a curing accelerator.
[10] Any one of [1] to [9], wherein the content of Si contained in component (A) is 0.2% by mass or more and 5% by mass or less, based on 100% by mass of component (A). The resin composition described in .
[11] Any one of [1] to [10], wherein the content of Cr contained in component (A) is 0.5% by mass or more and 6% by mass or less based on 100% by mass of component (A). The resin composition described.
[12] The resin composition according to any one of [1] to [11], wherein the amount of component (A) is 40% by mass or more based on 100% by mass of nonvolatile components in the resin composition.
[13] The resin composition according to any one of [1] to [12], wherein the amount of component (A) is 30% by volume or more based on 100% by volume of nonvolatile components in the resin composition.
[14] Any one of [2] to [13], wherein the total amount of component (A) and component (C) is 70% by mass or more based on 100% by mass of nonvolatile components in the resin composition. resin composition.
[15] The total amount of component (A) and component (C) is 50% by volume or more based on 100% by volume of nonvolatile components in the resin composition, according to any one of [2] to [14]. resin composition.
[16] The resin composition according to any one of [1] to [15], which is for hole filling.
[17] A cured product of the resin composition according to any one of [1] to [16].
[18] A magnetic paste comprising the resin composition according to any one of [1] to [16].
[19] Comprising a support and a resin composition layer provided on the support,
A resin sheet, wherein the resin composition layer contains the resin composition according to any one of [1] to [16].
[20] A circuit board comprising a substrate having holes, and a cured product of the resin composition according to any one of [1] to [16] filled in the holes.
[21] A circuit board comprising a cured product layer containing a cured product of the resin composition according to any one of [1] to [16].
[22] An inductor board comprising the circuit board according to [20] or [21].

According to the present invention, a resin composition with a low melt viscosity that can yield a cured product with high relative magnetic permeability and low magnetic loss; and a cured product of the resin composition; A magnetic paste and a resin sheet; and a circuit board and an inductor board containing a cured product of the resin composition described above can be provided.

FIG. 1 is a cross-sectional view schematically showing a core board prepared in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a core board in which through holes are formed in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a core substrate in which a plating layer is formed in a through hole in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing how a resin composition is filled into a through hole of a core substrate in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view for explaining step (2) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view for explaining step (3) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view for explaining step (5) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view for explaining step (5) of the method for manufacturing a circuit board according to the first example of the embodiment of the present invention. FIG. 9 is a schematic cross-sectional view for explaining step (i) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. FIG. 10 is a schematic cross-sectional view for explaining step (i) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. FIG. 11 is a schematic cross-sectional view for explaining step (ii) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. FIG. 12 is a schematic cross-sectional view for explaining step (iv) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. FIG. 13 is a schematic plan view of the circuit board included in the inductor board, viewed from one side in the thickness direction. FIG. 14 is a schematic diagram showing a cut end surface of the circuit board cut at the position indicated by the dashed line II-II in FIG. FIG. 15 is a schematic plan view for explaining the configuration of the first conductor layer of the circuit board included in the inductor board.

Hereinafter, the present invention will be explained in detail based on its preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and may be implemented with arbitrary changes within the scope of the claims and equivalents thereof.

In the following description, the "resin component" of the resin composition refers to the nonvolatile components contained in the resin composition excluding inorganic particles such as magnetic powder.

In the following description, "magnetic permeability" represents "relative magnetic permeability" unless otherwise specified.

<Resin composition>
The resin composition of the present invention is a resin composition containing (A) Fe-Ni-Si-Cr alloy magnetic powder and (B) a thermosetting resin, wherein Cr contained in the component (A) The content is 0.1% by mass or more and 6% by mass or less based on 100% by mass of component (A). According to such a resin composition, the melt viscosity is low, the relative magnetic permeability of the cured product of the resin composition can be increased, and the magnetic loss can be reduced.

The present inventor conjectures the mechanism by which such excellent effects are obtained by the resin composition according to the present embodiment as follows. Generally, FeNi alloy has a crystal structure formed of Fe and Ni, and therefore has high crystallinity. Therefore, while FeNi alloys have high relative magnetic permeability, they tend to have high magnetic loss. On the other hand, when Si and Cr are introduced into the FeNi alloy, the crystal structures of Fe and Ni are distorted. Therefore, it was predicted that the greater the amount of Si and Cr introduced, the greater the distortion of the crystal structure of Fe and Ni, and the greater the relative permeability and magnetic loss would be. However, the inventor's studies have revealed that the amount of reduction in magnetic loss can be increased by introducing Si. In addition, it has been conventionally believed that introducing Cr into FeNi alloys has a negative effect on the relative magnetic permeability, but the present inventor's study revealed that the amount of Cr is 0.1% by mass or more and 6% by mass or less. It has been found that the melt viscosity can be lowered when the viscosity is within this range. Therefore, the (A) Fe-Ni-Si-Cr alloy magnetic powder containing Si and Cr in amounts in the specific range exhibits high relative permeability due to the crystal structure of Fe and Ni, and It can exhibit a unique effect of effectively reducing magnetic loss, and can also lower melt viscosity. Therefore, due to the above-mentioned specific action of the (A) Fe-Ni-Si-Cr based alloy magnetic powder, the cured product of the resin composition described above has higher performance than conventional resin compositions containing magnetic powder. Melt viscosity can be lowered while maintaining relative permeability and magnetic loss.

However, the technical scope of the present invention is not limited by the above mechanism. In addition, in the explanation of the above mechanism, the case where Si and Cr are introduced into FeNi alloy was given as an example, but there are no restrictions on the manufacturing method of (A) Fe-Ni-Si-Cr alloy magnetic powder, and therefore, , Fe--Ni--Si--Cr alloy magnetic powders manufactured by methods other than introducing Si and Cr into FeNi alloys are also included in (A) Fe-Ni-Si-Cr alloy magnetic powders.

<(A) Fe-Ni-Si-Cr alloy magnetic powder>
The resin composition contains (A) Fe--Ni--Si--Cr based alloy magnetic powder as the (A) component. Therefore, (A) Fe--Ni--Si alloy magnetic powder contains a combination of Fe, Ni, Si, and Cr.

The content of Cr contained in the (A) Fe-Ni-Si-Cr alloy magnetic powder is 0.1 mass% with respect to 100 mass% of the (A) Fe-Ni-Si-Cr alloy magnetic powder. % or more, preferably 0.5% by mass or more, more preferably 1% by mass or more. The upper limit is 6% by mass or less, preferably 5.5% by mass or less, and more preferably 4% by mass or less. When the amount of Cr is within the above range, the melt viscosity of the resin composition can be lowered, and it is possible to achieve a good balance between increasing the relative magnetic permeability of the cured product of the resin composition and lowering the magnetic loss. .

The content of Si contained in the (A) Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.0% based on 100% by mass of the (A) Fe-Ni-Si-Cr alloy magnetic powder. 1% by mass or more, preferably 0.15% by mass or more, more preferably 0.2% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less. It is. When the amount of Si is within the above range, it is possible to lower the melt viscosity of the resin composition, and to achieve a good balance between increasing the relative magnetic permeability of the cured product of the resin composition and lowering the magnetic loss. .

(A) The mass ratio (Si/Fe) between the amount of Si and the amount of Fe contained in the Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.01 or more, more preferably 0.02 or more. , particularly preferably 0.04 or more, preferably 0.17 or less, more preferably 0.16 or less, particularly preferably 0.14 or less. When the ratio of the amount of Si to the amount of Fe (Si/Fe) is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

(A) The mass ratio (Si/Ni) between the amount of Si and the amount of Ni contained in the Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.01 or more, more preferably 0.02 or more. , particularly preferably 0.04 or more, preferably 0.21 or less, more preferably 0.20 or less, particularly preferably 0.18 or less. When the ratio of the amount of Si to the amount of Ni (Si/Ni) is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

(A) The mass ratio (Cr/Fe) between the amount of Cr and the amount of Fe contained in the Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.01 or more, more preferably 0.02 or more. , particularly preferably 0.04 or more, preferably 0.17 or less, more preferably 0.16 or less, particularly preferably 0.14 or less. When the ratio of the amount of Cr to the amount of Fe (Cr/Fe) is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively reduced. Can be done well.

(A) The mass ratio (Cr/Ni) between the amount of Cr and the amount of Ni contained in the Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.01 or more, more preferably 0.02 or more. , particularly preferably 0.04 or more, preferably 0.21 or less, more preferably 0.20 or less, particularly preferably 0.18 or less. When the ratio of the amount of Cr to the amount of Ni (Cr/Ni) is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively reduced. Can be done well.

The amount of Fe contained in the (A) Fe-Ni-Si-Cr alloy magnetic powder is preferably 33.00% by mass based on 100% by mass of the (A) Fe-Ni-Si-Cr alloy magnetic powder. % by mass or more, more preferably 38.00% by mass or more, still more preferably 43.00% by mass or more, particularly preferably 48.00% by mass or more, and preferably 65.00% by mass or less, more preferably 60.00% by mass or more. 00% by mass or less, more preferably 55.00% by mass or less, particularly preferably 52.00% by mass or less. When the amount of Fe is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount of Ni contained in the (A) Fe-Ni-Si-Cr alloy magnetic powder is preferably 33.00% by mass based on 100% by mass of the (A) Fe-Ni-Si-Cr alloy magnetic powder. % by mass or more, more preferably 38.00% by mass or more, still more preferably 40.00% by mass or more, particularly preferably 42.00% by mass or more, and preferably 65.00% by mass or less, more preferably 60.00% by mass or more. 00% by mass or less, more preferably 54.00% by mass or less, particularly preferably 49.00% by mass or less. When the amount of Ni is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

(A) The total amount of Fe and Ni contained in the Fe-Ni-Si-Cr alloy magnetic powder is preferably 85% by mass based on 100% by mass of the (A) Fe-Ni-Si alloy magnetic powder. % or more, more preferably 87% by mass or more, particularly preferably 92% by mass or more, preferably 99% by mass or less, more preferably 98.5% by mass or less, particularly preferably 98% by mass or less. When the total amount of Fe and Ni is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

(A) The mass ratio (Fe/Ni) between the amount of Fe and the amount of Ni contained in the Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.5 or more, more preferably 0.7 or more. , particularly preferably 1.0 or more, preferably 1.21 or less, more preferably 1.20 or less, particularly preferably 1.19 or less. When the ratio of the amount of Fe to the amount of Ni (Fe/Ni) is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

(A) The Fe--Ni--Si--Cr alloy magnetic powder may contain any element other than Fe, Ni, and Si. Examples of the arbitrary elements include (A) elements derived from impurities that may inevitably be mixed in depending on the method for producing the Fe--Ni--Si--Cr alloy magnetic powder. Specific examples of arbitrary elements include P, S, Mn, Mo, Cu, and Co. However, from the viewpoint of significantly exhibiting the effects of the present invention, it is preferable that (A) the Fe--Ni--Si--Cr alloy magnetic powder does not contain any elements other than Fe, Ni, Si, and Cr. Therefore, (A) Fe--Ni--Si--Cr based alloy magnetic powder preferably contains only Fe, Ni, Si, and Cr.

(A) The amount of Fe, Ni, Si, and Cr contained in the Fe-Ni-Si-Cr alloy magnetic powder was determined using an inductively coupled plasma optical emission spectrometer (for example, "ICP-OES 720ES" manufactured by Agilent Technologies). ”) can be measured.

(A) The average particle diameter (D50) of the Fe--Ni--Si--Cr alloy magnetic powder is preferably 1 μm or more, more preferably 2 μm or more, particularly preferably 3 μm or more. (A) When the average particle diameter (D50) of the Fe-Ni-Si-Cr alloy magnetic powder is greater than or equal to the lower limit, (A) Fe-Ni-Si-Cr alloy magnetic powder may be handled with preferred in terms of safety. Furthermore, when the average particle diameter (D50) of the (A) Fe-Ni-Si-Cr alloy magnetic powder is equal to or larger than the lower limit, the (A) Fe-Ni-Si-Cr alloy magnetic powder and ( B) Since the resin component including the thermosetting resin can be mixed with high uniformity, uneven distribution of the (A) Fe-Ni-Si-Cr alloy magnetic powder due to aggregation can be effectively suppressed. Therefore, the relative magnetic permeability and magnetic loss of the cured product can be effectively improved. (A) The upper limit of the average particle diameter (D50) of the Fe-Ni-Si-Cr alloy magnetic powder is preferably 10 μm or less, more preferably 9 μm or less, particularly preferably 7 μm or less. (A) When the average particle diameter (D50) of the Fe-Ni-Si-Cr alloy magnetic powder is less than or equal to the above upper limit, the particles of the (A) Fe-Ni-Si-Cr alloy magnetic powder are small. It can be something. Therefore, since the occurrence of large eddy current loss due to giant particles can be suppressed, magnetic loss can be effectively suppressed. This effect is particularly effective when the amount of (A) Fe--Ni--Si--Cr alloy magnetic powder is large.

(A) The average particle size (D50) of the Fe-Ni-Si-Cr alloy magnetic powder represents the volume-based median diameter unless otherwise specified. This average particle diameter (D50) can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, it can be measured by creating a particle size distribution on a volume basis using a laser diffraction scattering type particle size distribution measuring device, and setting the median diameter as the average particle size (D50). As the measurement sample, it is preferable to use a powder obtained by dispersing powder in water using ultrasonic waves. As the laser diffraction scattering particle size distribution measuring device, "LA-500" manufactured by Horiba, "SALD-2200" manufactured by Shimadzu Corporation, etc. can be used.

(A) The specific surface area of the Fe-Ni-Si-Cr alloy magnetic powder is preferably 0.05 m ² /g or more, more preferably 0.1 m ² /g or more, and even more preferably 0.5 m ² /g. or more, preferably 20 m ² /g or less, more preferably 10 m ² /g or less, even more preferably 5 m ² /g or less. (A) When the specific surface area of the Fe-Ni-Si-Cr alloy magnetic powder is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured resin composition can be reduced. can be effectively improved. The specific surface area of magnetic powder can be measured by the BET method. Specifically, the specific surface area can be measured using the BET multipoint method by adsorbing nitrogen gas onto the surface of the sample using a specific surface area measuring device ("Macsorb HM Model 1210" manufactured by Mountec).

(A) The particles of the Fe--Ni--Si--Cr alloy magnetic powder are preferably spherical. According to the study of the present inventors, particles of (A) Fe-Ni-Si-Cr alloy magnetic powder containing Si usually have a larger surface area than particles of FeNi alloy powder that does not contain Si and Cr. It can have a shape with few irregularities, and therefore can have a shape close to a sphere.

(A) The value (aspect ratio) obtained by dividing the length of the long axis of the particle of the Fe-Ni-Si-Cr based alloy magnetic powder by the length of the short axis (aspect ratio) is preferably 2 or less, more preferably 1.6. Below, it is more preferably 1.4 or below. (A) When the aspect ratio of the Fe-Ni-Si-Cr alloy magnetic powder is within the above range, magnetic loss can be suppressed and the melt viscosity of the resin composition can be lowered.

(A) There are no restrictions on the method for producing the Fe--Ni--Si--Cr alloy magnetic powder. (A) Fe--Ni--Si--Cr based alloy magnetic powder can be manufactured using, for example, an atomization method. In this atomization method, (A) Fe-Ni-Si is usually rapidly solidified by spraying high-pressure water or gas while dropping bath water containing melted iron, nickel, Si, and Cr. - Obtain Cr-based alloy magnetic powder. Among the atomization methods described above, a water atomization method in which water is sprayed onto falling bath water is preferred. As such an atomization method, for example, the method described in JP-A No. 2018-178254 can be adopted.

(A) The content (volume%) of the Fe-Ni-Si-Cr alloy magnetic powder is preferably 30% by volume or more, more preferably 40% by volume, based on 100% by volume of the nonvolatile components contained in the resin composition. The content is at least 50 volume%, particularly preferably at least 50 volume%, preferably at most 90 volume%, more preferably at most 80 volume%, particularly preferably at most 70 volume%. (A) When the amount of the Fe-Ni-Si-Cr alloy magnetic powder is within the above range, the relative magnetic permeability and magnetic loss of the cured resin composition can be effectively improved. In addition, when the amount of (A) Fe-Ni-Si-Cr alloy magnetic powder is below the upper limit of the above range, it usually effectively lowers the melt viscosity of the resin composition to easily form a paste. Can be done.

The volume-based amount (volume %) of each component contained in the resin composition is determined by calculation from the mass of the component contained in the resin composition. Specifically, the volume of each component is determined by dividing the mass by the specific gravity, and the volume-based amount (volume %) can be calculated from the volume of each component thus determined.

The content (mass%) of (A) Fe-Ni-Si-Cr alloy magnetic powder is preferably 40 mass% or more, more preferably 50 mass% or more, particularly preferably 55 mass% or more, and preferably 95 mass% or less, more preferably 90 mass% or less, particularly preferably 85 mass% or less, based on 100 mass% of non-volatile components contained in the resin composition. When the amount of (A) Fe-Ni-Si-Cr alloy magnetic powder is within the above range, the relative permeability and magnetic loss of the cured product of the resin composition can be effectively improved. Also, when the amount of (A) Fe-Ni-Si-Cr alloy magnetic powder is below the upper limit of the above range, the melt viscosity of the resin composition can usually be effectively lowered and it can be easily made into a paste.

The total amount of magnetic powder contained in the resin composition is usually expressed as the total amount of (A) Fe-Ni-Si-Cr alloy magnetic powder and (C) any magnetic powder described below. The total amount (volume %) of the magnetic powder contained in this resin composition is preferably 50 volume % or more, more preferably 60 volume % or more, and even more preferably is 65% by volume or more, particularly preferably 70% by volume or more, preferably 90% by volume or less, more preferably 86% by volume or less, particularly preferably 82% by volume or less. When the total amount of magnetic powder is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved. Moreover, when the total amount of magnetic powder is below the upper limit of the above range, the melt viscosity of the resin composition is usually effectively lowered and it can be easily made into a paste.

The total amount of magnetic powder contained in the resin composition is usually expressed as the total amount of (A) Fe-Ni-Si-Cr alloy magnetic powder and (C) any magnetic powder described below. The total amount (mass%) of magnetic powder contained in this resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably is 85% by mass or more, particularly preferably 90% by mass or more, preferably 99% by mass or less, more preferably 98% by mass or less, particularly preferably 97% by mass or less. When the total amount of magnetic powder is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved. Moreover, when the total amount of magnetic powder is below the upper limit of the above range, the melt viscosity of the resin composition is usually effectively lowered and it can be easily made into a paste.

<(B) Thermosetting resin>
The resin composition contains (B) a thermosetting resin as the (B) component. (B) Thermosetting resin can usually bind magnetic powder such as (A) Fe-Ni-Si-Cr alloy magnetic powder. Further, the thermosetting resin (B) usually reacts with heat to form a bond and can be cured. Therefore, a cured product can be obtained by curing a resin composition containing a combination of (A) Fe-Ni-Si-Cr alloy magnetic powder and (B) thermosetting resin. Since this cured product has excellent relative magnetic permeability and magnetic loss, it is possible to form an excellent magnetic layer.

(B) Examples of the thermosetting resin include epoxy resin, phenol resin, active ester resin, amine resin, acid anhydride resin, benzoxazine resin, cyanate ester resin, carbodiimide resin, etc. It will be done. (B) The thermosetting resin may be used alone or in combination of two or more.

(B) The thermosetting resin preferably includes (B-1) an epoxy resin. (B-1) Epoxy resin represents a resin having one or more epoxy groups in the molecule. (B) When the thermosetting resin contains (B-1) an epoxy resin, it is possible to increase the dispersibility of the (A) Fe-Ni-Si-Cr alloy magnetic powder, or increase the relative permeability of the cured resin composition. Magnetic property and magnetic loss can be effectively improved.

(B-1) Examples of epoxy resins include bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, phenol novolac type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, alicyclic epoxy resins having an ester skeleton, Examples of the epoxy resin include heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, naphthylene ether type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, naphthol novolac type epoxy resins, and other epoxy resins containing condensed ring skeletons, isocyanurate type epoxy resins, alkyleneoxy skeleton and butadiene skeleton-containing epoxy resins, and fluorene structure-containing epoxy resins. The epoxy resin (B-1) may be used alone or in combination of two or more.

(B-1) The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. (B-1) The proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, particularly Preferably it is 70% by mass or more.

(B-1) The epoxy resin preferably has an aromatic structure. When using two or more types of epoxy resins, it is preferable that one or more types of epoxy resins have an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatics and aromatic heterocycles.

(B-1) Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins"). ). (B-1) The epoxy resin may be only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. Among these, the epoxy resin (B-1) preferably contains a liquid epoxy resin, and particularly preferably contains only a liquid epoxy resin.

As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable. Liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolak type epoxy resin, and ester skeleton. Preferred are alicyclic epoxy resins, cyclohexane type epoxy resins, cyclohexanedimethanol type epoxy resins, epoxy resins having a butadiene structure, epoxy resins containing an alkyleneoxy skeleton and a butadiene skeleton, epoxy resins containing a fluorene structure, and dicyclopentadiene type epoxy resins. . Among these, bisphenol A type epoxy resin and bisphenol F type epoxy resin are particularly preferred.

Specific examples of liquid epoxy resins include "YX7400" manufactured by Mitsubishi Chemical; "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US" and "828EL" manufactured by Mitsubishi Chemical. ", "jER828EL", "825", "Epicote 828EL" (bisphenol A type epoxy resin); Mitsubishi Chemical's "jER807", "1750" (bisphenol F type epoxy resin); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); “630”, “630LSD”, “604” manufactured by Mitsubishi Chemical Corporation (glycidylamine type epoxy resin); “ED-523T” manufactured by ADEKA (glycyol type epoxy resin); ADEKA “EP-3950L” and “EP-3980S” (glycidylamine type epoxy resin) manufactured by ADEKA; “EP-4088S” (dicyclopentadiene type epoxy resin) manufactured by ADEKA; “ZX-” manufactured by Nippon Steel Chemical & Materials 1059” (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); “EX-721” (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX; “EX-991L” manufactured by Nagase ChemteX ( (alkyleneoxy skeleton-containing epoxy resins); “Celoxide 2021P” and “Celoxide 2081” (alicyclic epoxy resins having an ester skeleton) manufactured by Daicel; “PB-3600” manufactured by Daicel; “JP” manufactured by Nippon Soda -100", "JP-200" (epoxy resin having a butadiene structure); "ZX-1658", "ZX-1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical &Materials; Examples include "EG-280" (fluorene structure-containing epoxy resin) manufactured by Osaka Gas Chemical Co., Ltd. One type of liquid epoxy resin may be used alone, or two or more types may be used in combination.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable. Solid epoxy resins include bixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, and biphenyl. Type epoxy resins, naphthylene ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, and tetraphenylethane type epoxy resins are preferred, and dicyclopentadiene type epoxy resins are particularly preferred.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin) manufactured by DIC; “N-690” (cresol novolak type epoxy resin) manufactured by DIC; “N-695” (cresol novolac type epoxy resin) manufactured by DIC; “HP-7200”, “HP-7200HH”, “HP” manufactured by DIC -7200H" (dicyclopentadiene type epoxy resin); DIC's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" ( naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku; "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical &Materials; "ESN485" manufactured by Nippon Steel Chemical & Materials ” (naphthol novolac type epoxy resin); “YX4000H”, “YX4000”, “YL6121” manufactured by Mitsubishi Chemical (biphenyl type epoxy resin); “YX4000HK” manufactured by Mitsubishi Chemical (bixylenol type epoxy resin); Mitsubishi Chemical “YX8800” (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Company; “YX7700” (novolac type epoxy resin containing xylene structure) manufactured by Mitsubishi Chemical Company; “PG-100” and “CG-500” manufactured by Osaka Gas Chemical Company; "YL7760" (bisphenol AF type epoxy resin) manufactured by Chemical Company; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Company; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Company; Examples include "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Co., Ltd. One type of solid epoxy resin may be used alone, or two or more types may be used in combination.

When using a combination of a liquid epoxy resin and a solid epoxy resin as the epoxy resin, the mass ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin/solid epoxy resin) is preferably 0.5 or more, More preferably, it is 1 or more, still more preferably 5 or more, particularly preferably 10 or more.

(B-1) The epoxy equivalent of the epoxy resin is preferably 50 g/eq. ～5000g/eq. , more preferably 50g/eq. ～3000g/eq. , more preferably 80g/eq. ～2000g/eq. , even more preferably 110 g/eq. ～1000g/eq. It is. Epoxy equivalent is the mass of resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

(B-1) The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured as a value in terms of polystyrene by gel permeation chromatography (GPC).

The amount (% by mass) of the epoxy resin (B-1) contained in the resin composition is preferably 0.1% by mass or more, more preferably 0.5% by mass, based on 100% by mass of the nonvolatile components of the resin composition. % or more, particularly preferably 1% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, particularly preferably 3% by mass or less. (B-1) When the amount of the epoxy resin is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount (mass %) of the (B-1) epoxy resin contained in the resin composition is preferably 20 mass % or more, more preferably 30 mass % or more, particularly preferably 40 mass % or more, and preferably 90 mass % or less, more preferably 80 mass % or less, particularly preferably 70 mass % or less, based on 100 mass % of the resin components of the resin composition. When the amount of (B-1) epoxy resin is within the above range, the melt viscosity of the resin composition can be reduced, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

When the (B) thermosetting resin contains (B-1) an epoxy resin, the (B) thermosetting resin may contain a resin that can react with and bond to the (B-1) epoxy resin. (B-1) A resin capable of reacting and bonding with an epoxy resin is sometimes referred to as "(B-2) curing agent" hereinafter. (B-2) Examples of the curing agent include phenolic resins, active ester resins, amine resins, carbodiimide resins, acid anhydride resins, benzoxazine resins, cyanate ester resins, and thiol resins. Can be mentioned. (B-2) One type of curing agent may be used alone, or two or more types may be used in combination. Among these, phenolic resins are preferred.

As the phenolic resin, a resin having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring in one molecule can be used. From the viewpoint of heat resistance and water resistance, phenolic resins having a novolak structure are preferred. From the viewpoint of adhesion, nitrogen-containing phenolic resins are preferred, and triazine skeleton-containing phenolic resins are more preferred. Among these, triazine skeleton-containing phenol novolac resins are preferred from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion.

Specific examples of phenolic resins include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", "SN-375", and "SN -395"; DIC's "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165"; Gun-ei Chemical's "GDP-6115L", "GDP-6115H", and "ELPC75", etc.

As the active ester resin, a compound having one or more, preferably two or more active ester groups in one molecule can be used. Among these, active ester resins include those having two or more ester groups with high reaction activity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds are preferred. The active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, active ester resins obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester resins obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenolic compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Examples include benzenetriol, dicyclopentadiene type diphenol compounds, and phenol novolacs. Here, the term "dicyclopentadiene type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Preferred specific examples of active ester resins include active ester resins containing a dicyclopentadiene type diphenol structure, active ester resins containing a naphthalene structure, active ester resins containing an acetylated product of phenol novolak, and benzoyl phenol novolac. Examples include active ester resins containing compounds. Among these, active ester resins containing a naphthalene structure and active ester resins containing a dicyclopentadiene type diphenol structure are more preferable. "Dicyclopentadiene type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester resins include "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," and "HPC-8000H-" as active ester resins containing a dicyclopentadiene diphenol structure. 65TM", "EXB-8000L-65TM" (manufactured by DIC Corporation); "EXB-9416-70BK", "EXB-8150-65T", "EXB-8100L-65T", " "EXB-8150L-65T" (manufactured by DIC Corporation); "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin containing an acetylated product of phenol novolak; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester resin containing a benzoylated product of phenol novolak. "DC808" (manufactured by Mitsubishi Chemical) as an active ester resin that is an acetylated product of phenol novolac; "YLH1026" (manufactured by Mitsubishi Chemical) as an active ester resin that is a benzoylated product of phenol novolak; Examples include "YLH1030" (manufactured by Mitsubishi Chemical Corporation) and "YLH1048" (manufactured by Mitsubishi Chemical Corporation).

As the amine resin, a resin having one or more, preferably two or more amino groups in one molecule can be used. Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Among these, aromatic amines are preferred. The amine resin is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of amine resins include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 3,3'- Diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4 , 4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine , 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis (4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis (4-(3-aminophenoxy)phenyl)sulfone, and the like. Commercially available amine resins may be used, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYA HARD AA", "KAYA HARD AB", and "KAYA HARD" manufactured by Nippon Kayaku Co., Ltd. Examples include "A-S" and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

As the carbodiimide resin, a resin having one or more, preferably two or more carbodiimide structures in one molecule can be used. Specific examples of carbodiimide resins include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexanebis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); Biscarbodiimides such as carbodiimide; aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly (naphthylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), Examples include polycarbodiimides such as aromatic polycarbodiimides such as poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylene diphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. Commercially available carbodiimide resins include, for example, "Carbodilite V-02B", "Carbodilite V-03", "Carbodilite V-04K", "Carbodilite V-07", and "Carbodilite V-09" manufactured by Nisshinbo Chemical Co., Ltd. ; Examples include "Stavaxol P", "Stavaxol P400", and "Hikasil 510" manufactured by Rhein Chemie.

As the acid anhydride resin, a resin having one or more acid anhydride groups in one molecule can be used, and a resin having two or more acid anhydride groups in one molecule is preferable. Specific examples of acid anhydride resins include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, and hydrogenated methylnadic anhydride. trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride Acid, pyromellitic anhydride, bensophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenyl Sulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1, Examples include polymeric acid anhydrides such as 3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resin, which is a copolymer of styrene and maleic acid. Commercially available acid anhydride resins include, for example, "HNA-100", "MH-700", "MTA-15", "DDSA", and "OSA" manufactured by Shin Nippon Chemical Co., Ltd.; and "OSA" manufactured by Mitsubishi Chemical Corporation. "YH-306", "YH-307"; "HN-2200", "HN-5500" manufactured by Hitachi Chemical; "EF-30", "EF-40", "EF-60", manufactured by Clay Valley EF-80'', etc.

Specific examples of benzoxazine resins include "JBZ-OD100", "JBZ-OP100D", and "ODA-BOZ" manufactured by JFE Chemical; "P-d" and "F-a" manufactured by Shikoku Kasei Kogyo Co., Ltd. ; Examples include "HFB2006M" manufactured by Showa Kobunshi Co., Ltd.

Examples of cyanate ester resins include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins have been partially converted to triazine. Specific examples of cyanate ester resins include Lonza Japan's "PT30" and "PT60" (phenol novolac type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resin), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been converted to triazine and formed into a trimer).

Examples of the thiol resin include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), tris(3-mercaptopropyl)isocyanurate, and the like.

(B-2) The active group equivalent of the curing agent is preferably 50 g/eq. ～3000g/eq. , more preferably 100g/eq. ～1000g/eq. , more preferably 100g/eq. ～500g/eq. , particularly preferably 100 g/eq. ～300g/eq. It is. The active group equivalent represents the mass of the (B-2) curing agent per equivalent of the active group.

When the number of epoxy groups in the (B-1) epoxy resin is taken as 1, the number of active groups in the (B-2) curing agent is preferably 0.01 or more, more preferably 0.1 or more, particularly preferably 0.5 or more, and preferably 10 or less, more preferably 5 or less, particularly preferably 3 or less. The active groups in the (B-2) curing agent are active hydroxyl groups, etc., and differ depending on the type of curing agent. The number of epoxy groups in the (B-1) epoxy resin is the total value for all epoxy resins obtained by dividing the non-volatile component mass of each epoxy resin by the epoxy equivalent. The number of active groups in the (B-2) curing agent is the total value for all curing agents obtained by dividing the non-volatile component mass of each curing agent by the active group equivalent.

The amount (mass %) of the curing agent (B-2) contained in the resin composition is preferably 0.1 mass % or more, more preferably 0.5 mass %, based on 100 mass % of the nonvolatile components of the resin composition. % or more, particularly preferably 1% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, particularly preferably 3% by mass or less. (B-2) When the amount of the curing agent is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount (mass%) of the curing agent (B-2) contained in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, particularly The content is preferably 30% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, particularly preferably 40% by mass or less. (B-2) When the amount of the curing agent is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The range of the weight average molecular weight (Mw) of the thermosetting resin (B) can usually be the same as the range of the weight average molecular weight of the epoxy resin (B-1) described above.

The amount (mass %) of the thermosetting resin (B) contained in the resin composition is preferably 0.1 mass % or more, more preferably 0.5 mass %, based on 100 mass % of the nonvolatile components of the resin composition. % or more, particularly preferably 1% by mass or more, preferably 30% by mass or less, more preferably 20% by mass or less, particularly preferably 10% by mass or less. (B) When the amount of the thermosetting resin is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount (mass%) of the thermosetting resin (B) contained in the resin composition is preferably 30% by mass or more, more preferably 50% by mass or more, particularly The content is preferably 60% by mass or more, preferably 99% by mass or less, more preferably 90% by mass or less, particularly preferably 85% by mass or less. (B) When the amount of the thermosetting resin is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The total amount (mass%) of (A) Fe-Ni-Si-Cr alloy magnetic powder and (B) thermosetting resin is preferably 50% by mass based on 100% by mass of the nonvolatile components of the resin composition. The above is more preferably 55% by mass or more, particularly preferably 60% by mass or more, preferably 100% by mass or less, more preferably 95% by mass or less, particularly preferably 90% by mass or less, or 85% by mass or less. . (B) When the amount of the thermosetting resin is within the above range, the melt viscosity of the resin composition can be lowered, and the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

<(C) Any magnetic powder (magnetic powder other than Fe-Ni-Si-Cr alloy magnetic powder)>
The resin composition may further contain magnetic powder other than (C) Fe-Ni-Si-Cr alloy magnetic powder as an optional component in combination with the above-mentioned components (A) to (B). . The "(C) magnetic powder other than the Fe--Ni--Si--Cr alloy magnetic powder" as the component (C) may be appropriately referred to as "(C) any magnetic powder."

(C) As the optional magnetic powder, particles of a material having a relative magnetic permeability greater than 1 can be used. (C) The material of the arbitrary magnetic powder is usually an inorganic material, and may be a soft magnetic material or a hard magnetic material. Furthermore, (C) any magnetic powder material may be used alone or in combination of two or more. Therefore, the arbitrary magnetic powder (C) may be a soft magnetic powder, a hard magnetic powder, or a combination of a soft magnetic powder and a hard magnetic powder. Moreover, (C) arbitrary magnetic powder may be used individually, and may be used in combination of two or more types. Among these, (C) any magnetic powder preferably contains soft magnetic powder, and more preferably contains only soft magnetic powder.

(C) Examples of the arbitrary magnetic powder include magnetic metal oxide powder and magnetic metal powder.

Examples of the magnetic metal oxide powder include ferrite-based magnetic powder; and iron oxide powder such as iron oxide powder (III) and triiron tetroxide powder. Among these, ferrite magnetic powder is preferred. Therefore, (C) any magnetic powder preferably includes ferrite magnetic powder. In one example, only ferrite-based magnetic powder may be used as the arbitrary magnetic powder (C). Ferrite-based magnetic powder usually consists of a complex oxide containing iron oxide as a main component, and is chemically stable. Therefore, ferrite-based magnetic powder has advantages such as high corrosion resistance, low risk of ignition, and resistance to demagnetization.

Examples of the ferrite magnetic powder include Fe-Mn ferrite powder, Fe-Mn-Zn ferrite powder, Fe-Mn-Mg ferrite powder, and Fe-Mn-Mg-Sr ferrite powder. , Fe-Mg-Zn ferrite powder, Fe-Mg-Sr ferrite powder, Fe-Zn-Mn ferrite powder, Fe-Cu-Zn ferrite powder, Fe-Ni-Zn ferrite powder , Fe-Ni-Zn-Cu ferrite powder, Fe-Ba-Zn ferrite powder, Fe-Ba-Mg ferrite powder, Fe-Ba-Ni ferrite powder, Fe-Ba-Co ferrite Examples include powder, Fe-Ba-Ni-Co ferrite powder, Fe-Y ferrite powder, and the like.

Among ferrite-based magnetic powders, ferrite-based magnetic powders containing at least one element selected from the group consisting of Mn, Zn, Ni, and Cu are preferred. Therefore, (C) any magnetic powder preferably includes ferrite-based magnetic powder containing at least one element selected from the group consisting of Mn, Zn, Ni, and Cu. In one example, as the arbitrary magnetic powder (C), only ferrite magnetic powder containing at least one element selected from the group consisting of Mn, Zn, Ni, and Cu may be used. As such, preferable ferrite magnetic powders include, for example, Fe--Mn-based ferrite powder, Fe--Mn--Zn-based ferrite powder, Fe--Mn--Mg-based ferrite powder, Fe--Mn--Mg--Sr. ferrite powder, Fe-Mg-Zn ferrite powder, Fe-Zn-Mn ferrite powder, Fe-Cu-Zn ferrite powder, Fe-Ni-Zn ferrite powder, Fe-Ni-Zn Examples include -Cu ferrite powder, Fe-Ba-Zn ferrite powder, Fe-Ba-Ni ferrite powder, and Fe-Ba-Ni-Co ferrite powder. Among these, ferrite magnetic powder containing at least one element selected from the group consisting of Zn and Mn is more preferred, and ferrite magnetic powder containing Zn and Mn is particularly preferred. Therefore, as the ferrite magnetic powder, Fe--Mn--Zn-based ferrite powder and Fe--Mn-based ferrite powder are preferred, and Fe--Mn--Zn-based ferrite powder is particularly preferred. Fe--Zn--Mn-based ferrite powder represents ferrite powder containing Fe, Zn, and Mn, and Fe--Mn-based ferrite powder represents ferrite powder containing Fe and Mn.

Examples of the magnetic metal powder include pure iron powder; Fe-Mn-Zn alloy powder, Fe-Si alloy powder, Fe-Mn alloy powder, Fe-Si-Al alloy powder, Fe-Cr alloy powder, Fe-Cr-Si alloy powder, Fe-Ni-Cr alloy powder, Fe-Cr-Al alloy powder, Fe-Ni alloy powder, Fe-Ni- B-based alloy powder, Fe-Ni-Mo-based alloy powder, Fe-Ni-Mo-Cu-based alloy powder, Fe-Co-based alloy powder, Fe-Ni-Co-based alloy powder, Co-based amorphous alloy Examples include crystalline or amorphous alloy magnetic powder such as powder. Among these, alloy magnetic powders other than Fe-Ni-Si-Cr alloy magnetic powders are preferred. Therefore, (C) the optional magnetic powder preferably includes an alloy magnetic powder other than the Fe-Ni-Si-Cr alloy magnetic powder. In one example, as the arbitrary magnetic powder (C), only alloy magnetic powder other than Fe-Ni-Si-Cr alloy magnetic powder may be used. Furthermore, among the alloy magnetic powders, iron alloy powders are more preferable.

Particularly preferred magnetic metal powders are iron alloy magnetic powders containing Fe and at least one element selected from the group consisting of Si and Cr, and particularly preferred are Fe-Cr-Si alloy powders. . Fe-Cr-Si alloy powder refers to alloy powder containing Fe, Cr and Si.

(C) As the arbitrary magnetic powder, commercially available magnetic powder may be used. Specific examples of commercially available magnetic powders include "MZ03S", "M03S", "M05S", "M001", "MZ05S" manufactured by Powder Tech; "PST-S" manufactured by Sanyo Special Steel; and "PST-S" manufactured by Epson Atomics. "AW2-08", "AW2-08PF20F", "AW2-08PF10F", "AW2-08PF3F", "Fe-3.5Si-4.5CrPF20F", "Fe-50NiPF20F", "Fe-80Ni-4MoPF20F"; "CVD iron powder 0.7μm", "LD-M", "LD-MH", "KNI-106", "KNI-106GSM", "KNI-106GS", "KNI-109", "KNI-109", "KNI-106GSM", KNI-109GSM", "KNI-109GS"; Toda Kogyo's "KNS-415", "BSF-547", "BSF-029", "BSN-125", "BSN-125", "BSN-714" , "BSN-828", "S-1281", "S-1641", "S-1651", "S-1470", "S-1511", "S-2430"; "JR09P2" manufactured by Japan Heavy Chemical Industry Co., Ltd. "; "Nanotek" manufactured by CIK Nanotech; "JEMK-S" and "JEMK-H" manufactured by Kinsei Matek; "Yttrium iron oxide" manufactured by ALDRICH; "MA-RCO-5" manufactured by DOWA Electronics; It will be done. (C) Any magnetic powder may be used alone or in combination of two or more.

(C) Any magnetic powder preferably has a smaller average particle size than (A) Fe-Ni-Si-Cr alloy magnetic powder. (C) If any magnetic powder has an average particle size smaller than (A) the Fe-Ni-Si-Cr alloy magnetic powder, the (A) Fe-Ni-Si-Cr alloy magnetic powder Since any magnetic powder (C) can be inserted into the gaps between the particles, high filling of the magnetic powder is possible, and thus magnetic properties such as relative magnetic permeability can be improved.

(A) Ratio of the average particle size of any magnetic powder to (C) the average particle size of the Fe-Ni-Si-Cr alloy magnetic powder ((C) Average particle size of any magnetic powder/(A ) The average particle size of the Fe--Ni--Si--Cr alloy magnetic powder) is preferably within a specific range. Specifically, the ratio ((C) average particle size of any magnetic powder/(A) average particle size of Fe-Ni-Si-Cr alloy magnetic powder) is preferably 0.001 or more. , more preferably 0.01 or more, particularly preferably 0.05 or more, preferably 0.9 or less, more preferably 0.6 or less, particularly preferably 0.3 or less. When the ratio ((C) average particle size of arbitrary magnetic powder/(A) average particle size of Fe-Ni-Si-Cr alloy magnetic powder) is within the above range, the cured product of the resin composition Relative magnetic permeability and magnetic loss can be effectively improved.

(C) The specific range of the average particle size of the arbitrary magnetic powder is preferably 0.05 μm or more, more preferably 0.1 μm or more, particularly preferably 0.2 μm or more, and preferably 3 μm or less, more preferably The thickness is preferably 2 μm or less, particularly preferably 1.5 μm or less. (C) When the average particle size of the arbitrary magnetic powder is equal to or larger than the lower limit, the viscosity of the resin composition can be lowered. Moreover, when it is below the upper limit, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

(C) The average particle size of any magnetic powder can be measured by the same method as the average particle size of (A) Fe-Ni-Si-Cr alloy magnetic powder.

(C) The specific surface area of the arbitrary magnetic powder is preferably larger than the specific surface area of (A) the Fe--Ni--Si--Cr alloy magnetic powder. (C) The specific range of the specific surface area of any magnetic powder is preferably 0.1 m ² /g or more, more preferably 1.0 m ² /g or more, particularly preferably 2 m ² /g or more, Preferably it is 40 m ² /g or less, more preferably 30 m ² /g or less, particularly preferably 20 m ² /g or less.

(C) The particles of the arbitrary magnetic powder are preferably spherical or ellipsoidal particles. (C) The ratio (aspect ratio) of the length of the long axis of the particle of any magnetic powder divided by the length of the short axis is preferably 2 or less, more preferably 1.5 or less, and even more preferably 1. 2 or less, and usually 1.0 or more. Generally, when the shape of the particles of magnetic powder is flat rather than spherical, the relative magnetic permeability can be easily improved. On the other hand, if the shape of the magnetic powder particles is close to spherical, magnetic loss can be easily reduced.

(C) The true specific gravity of any magnetic powder may be, for example, 4 g/cm ³ to 10 g/cm ³ .

The amount (volume %) of the arbitrary magnetic powder (C) contained in the resin composition may be 0 volume % or larger than 0 volume % with respect to 100 volume % of the nonvolatile components of the resin composition. The content is preferably 1% by volume or more, more preferably 5% by volume or more, particularly preferably 10% by volume or more, and preferably 40% by volume or less, more preferably 35% by volume or less, particularly preferably 30% by volume or less. (C) When the amount (volume %) of the arbitrary magnetic powder is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount (mass%) of the optional magnetic powder (C) contained in the resin composition may be 0% by mass or greater than 0% by mass, based on 100% by mass of the nonvolatile components of the resin composition. The content is preferably 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, particularly preferably 30% by mass or less. (C) When the amount (mass %) of the arbitrary magnetic powder is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

When using a combination of (A) Fe-Ni-Si-Cr alloy magnetic powder and (C) any magnetic powder, (C) for (A) Fe-Ni-Si-Cr alloy magnetic powder The volume ratio (component (C)/component (A)) of any magnetic powder is preferably within a specific range. Specifically, the volume ratio (component (C)/component (A)) is preferably 0.01 or more, more preferably 0.1 or more, still more preferably 0.2 or more, particularly preferably 0. It is 3 or more, preferably 0.9 or less, more preferably 0.8 or less, particularly preferably 0.7 or less. When the volume ratio (component (C)/component (A)) is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

When using a combination of (A) Fe-Ni-Si-Cr alloy magnetic powder and (C) any magnetic powder, (C) for (A) Fe-Ni-Si-Cr alloy magnetic powder The mass ratio (component (C)/component (A)) of any magnetic powder is preferably within a specific range. Specifically, the mass ratio (component (C)/component (A)) is preferably 0.1 or more, more preferably 0.15 or more, particularly preferably 0.2 or more, and preferably 1 Below, it is more preferably 0.8 or less, particularly preferably 0.7 or less. When the mass ratio (component (C)/component (A)) is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

<(D) Thermoplastic resin>
The resin composition may further contain (D) a thermoplastic resin as an optional component in combination with the above-mentioned components (A) to (C). The thermoplastic resin (D) as the component (D) does not include those corresponding to the components (A) to (C) described above. (D) According to the thermoplastic resin, the mechanical properties of the cured product of the resin composition can be effectively improved.

(D) Thermoplastic resins include, for example, phenoxy resins, polyimide resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, and polycarbonate resins. , polyetheretherketone resin, polyester resin, and the like. (D) The thermoplastic resin may be used alone or in combination of two or more.

Examples of the phenoxy resin include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7482" and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation; and the like.

Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shinnihon Rika Co., Ltd., and the like. Specific examples of polyimide resins include linear polyimides obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, diisocyanate compounds, and tetrabasic acid anhydrides (polyimide described in JP-A No. 2006-37083), polysiloxane skeletons, etc. Examples include modified polyimides such as polyimides containing polyimides (polyimides described in JP-A-2002-12667 and JP-A-2000-319386, etc.).

Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resin include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP manufactured by Denki Kagaku Kogyo; Sekisui Chemical Co., Ltd. Examples include the S-LEC BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by the company.

Examples of polyolefin resins include ethylene copolymers such as low density polyethylene, ultra-low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer. Resin; Examples include polyolefin polymers such as polypropylene and ethylene-propylene block copolymers.

Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxyl group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, and isocyanate group-containing polybutadiene resins. Examples include polybutadiene resin, urethane group-containing polybutadiene resin, polyphenylene ether-polybutadiene resin, and the like.

Specific examples of the polyamide-imide resin include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyobo. Specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imide) manufactured by Hitachi Chemical.

A specific example of the polyether sulfone resin includes "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

A specific example of the polyphenylene ether resin includes "NORYL SA90" manufactured by SABIC. A specific example of the polyetherimide resin includes "Ultem" manufactured by GE.

Examples of the polycarbonate resin include hydroxy group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxy group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, urethane group-containing carbonate resins, and the like. Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemicals, and "C-1090" and "C-2090" manufactured by Kuraray Corporation. , "C-3090" (polycarbonate diol), and the like. Specific examples of polyetheretherketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd., and the like.

Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, polycyclohexane dimethyl terephthalate resin, and the like.

The weight average molecular weight (Mw) of the thermoplastic resin (D) is preferably greater than 5,000, more preferably 8,000 or more, still more preferably 10,000 or more, particularly preferably 20,000 or more. The upper limit is not particularly limited, and may be, for example, 1 million or less, 500,000 or less, 100,000 or less, etc.

The amount (mass %) of the thermoplastic resin (D) contained in the resin composition may be 0 mass % or greater than 0 mass %, based on 100 mass % of the nonvolatile components of the resin composition. 0.01% by mass or more, more preferably 0.05% by mass or more, particularly preferably 0.1% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, particularly preferably 2% by mass. It is as follows. (D) When the amount of the thermoplastic resin is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount (mass %) of the (D) thermoplastic resin contained in the resin composition may be 0 mass % or more, and is preferably 1 mass % or more, more preferably 2 mass % or more, particularly preferably 3 mass % or more, and is preferably 15 mass % or less, more preferably 10 mass % or less, particularly preferably 5 mass % or less, based on 100 mass % of the resin components of the resin composition. When the amount of the (D) thermoplastic resin is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

<(E) Dispersant>
The resin composition according to one embodiment of the present invention may further contain (E) a dispersant as an optional component in combination with the above-mentioned components (A) to (D). The dispersant (E) as component (E) does not include those corresponding to components (A) to (D) described above. The dispersant (E) can improve the dispersibility of magnetic powders such as (A) Fe-Ni-Si-Cr alloy magnetic powder and (C) any magnetic powder.

(E) There are no restrictions on the type of dispersant. For example, (E) the dispersant contains a functional group that has adsorption ability to magnetic powder, and when adsorbed to the magnetic powder, (E) repulsion between the dispersants (e.g. electrostatic repulsion) occurs. , steric repulsion, etc.) can be used. Examples of such dispersants (E) include acidic dispersants and basic dispersants.

Acidic dispersants usually include a carboxyl group, a sulfo group (-SO ₃ H), a sulfuric acid group (-OSO ₃ H), a phosphono group (-PO(OH) ₂ ), a phosphonooxy group (-OPO(OH) ₂ ), Contains acidic functional groups such as hydroxyphosphoryl group (-PO(OH)-) and sulfanyl group (-SH). The acidic functional group usually has a dissociative proton and may be neutralized with a base such as an amine or a hydroxide ion. Preferred acidic dispersants include, for example, acidic polymer dispersants containing polymer chains such as polyoxyalkylene chains and polyether chains. Preferred examples of acidic dispersants include "C-2093I" and "SC-1015F" manufactured by NOF Corporation (a multifunctional comb-shaped functional polymer having an ionic group in the main chain and a polyoxyalkylene chain in the graft chain). ";"ED152","ED153","ED154","ED118","ED174","ED251","DA-375" manufactured by Kusumoto Kasei Co., Ltd. (polyether type phosphate ester dispersant); Toho Chemical "RS-410", "RS-610", "RS-710" (pH 1.9) (phosphate ester dispersant) of the "Phosphanol" series manufactured by Kogyo; "Marialim" manufactured by NOF Corporation Examples include the series "AKM-0531,""AFB-1521,""SC-0505K," and "SC-0708A."

Basic dispersants usually include bases such as primary, secondary, and tertiary amino groups; ammonium groups; imino groups; and nitrogen-containing heterocyclic groups such as pyridine, pyrimidine, pyrazine, imidazole, and triazole. Contains a sexual functional group. The basic functional group may be neutralized with an acid such as an organic acid or an inorganic acid. Preferred basic dispersants include, for example, basic polymer dispersants containing polymer chains such as polyester chains. A preferred example of the basic dispersant includes "PB-881" (a polyamine dispersant containing a polyester chain) manufactured by Ajinomoto Fine Techno.

(E) Dispersants may be used alone or in combination of two or more.

The amount (mass%) of the dispersant (E) contained in the resin composition may be 0% by mass or greater than 0% by mass, preferably 0% by mass, based on 100% by mass of the nonvolatile components of the resin composition. .01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, particularly preferably 2% by mass or less. It is. (E) When the amount of the dispersant is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

The amount (mass%) of the dispersant (E) contained in the resin composition may be 0% by mass or greater than 0% by mass, preferably 1% by mass, based on 100% by mass of the resin component of the resin composition. The content is at least 3% by mass, more preferably at least 3% by mass, particularly preferably at least 5% by mass, and preferably at most 30% by mass, more preferably at most 25% by mass, particularly preferably at most 20% by mass. (E) When the amount of the dispersant is within the above range, the relative magnetic permeability and magnetic loss of the cured product of the resin composition can be effectively improved.

<(F) Curing accelerator>
The resin composition may further contain (F) a curing accelerator as an optional component in combination with the above-mentioned components (A) to (E). The curing accelerator (F) as component (F) does not include those corresponding to the above-mentioned components (A) to (E). Since the curing accelerator (F) has a function as a catalyst for the reaction of the thermosetting resin (B), it can accelerate curing of the resin composition.

(F) Examples of the curing accelerator include phosphorus-based curing accelerators, imidazole-based curing accelerators, amine-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, urea-based curing accelerators, etc. . (F) The curing accelerator may be used alone or in combination of two or more. Among these, as the curing accelerator (F), phosphorus-based curing accelerators and imidazole-based curing accelerators are preferable, and phosphorus-based curing accelerators are more preferable.

Examples of the phosphorus curing accelerator include phosphonium salts and phosphine. Examples of the phosphonium salt include tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, n-butylphosphonium tetraphenylborate, and bis(tetrabutylphosphonium)pyromellitate. , tetrabutylphosphonium hydrogen hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, di-tert-butylmethylphosphonium tetraphenylborate, etc. Aliphatic phosphonium salts; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p- Tolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrap-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetra Examples include aromatic phosphonium salts such as phenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate.

Examples of the phosphine include tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl (2-butenyl) phosphine, di-tert-butyl (3-methyl-2-butenyl) phosphine, tricyclohexyl Aliphatic phosphine such as phosphine; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m- Tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4- tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine , tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4 -ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1, Aromatic phosphines such as 4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, 2,2'-bis(diphenylphosphino)diphenyl ether; Aromatics such as triphenylphosphine and triphenylborane Examples include aromatic phosphine/quinone addition reaction products such as triphenylphosphine/p-benzoquinone addition reaction products.

As the phosphorus-based curing accelerator, commercially available products may be used, such as "TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd., and the like.

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-Phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecyl imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4- Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2- Phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline , 2-phenylimidazoline and other imidazole compounds, and adducts of imidazole compounds and epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred. As the imidazole curing accelerator, commercially available products may be used, such as "P200-H50" manufactured by Mitsubishi Chemical; "Curezol 2MZ", "2E4MZ", "Cl1Z", and "Cl1Z" manufactured by Shikoku Kasei Kogyo Co., Ltd. -CN", "Cl1Z-CNS", "Cl1Z-A", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2MZA-PW", "2PHZ", "2PHZ-PW ”, “1B2PZ”, “1B2PZ-10M”, etc.

Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo. (5,4,0)-undecene, 1,8-diazabicyclo[5,4,0]undecene-7,4-dimethylaminopyridine, 2,4,6-tris(dimethylaminomethyl)phenol, etc. 4-dimethylaminopyridine is preferred. As the amine curing accelerator, commercially available products may be used, such as "PN-50", "PN-23", and "MY-25" manufactured by Ajinomoto Fine Techno.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, etc., and dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are preferred.

Examples of the metal hardening accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples include organic zinc complexes such as , organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

Examples of the urea-based curing accelerator include 1,1-dimethylurea; 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, 3- Aliphatic dimethylurea such as cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl) )-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4- methylphenyl)-1,1-dimethylurea, 3-(3,4-dimethylphenyl)-1,1-dimethylurea, 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4- methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3- [4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene) Aromatic dimethylurea such as bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea] etc.

The amount (mass %) of the curing accelerator (F) contained in the resin composition may be 0 mass % or greater than 0 mass %, based on 100 mass % of the nonvolatile components of the resin composition. 0.001% by mass or more, more preferably 0.005% by mass or more, particularly preferably 0.01% by mass or more, preferably 3% by mass or less, more preferably 2% by mass or less, particularly preferably 1% by mass. It is as follows.

The amount (mass %) of the curing accelerator (F) contained in the resin composition may be 0 mass % or greater than 0 mass %, based on 100 mass % of the resin component of the resin composition. 0.1% by mass or more, more preferably 0.3% by mass or more, particularly preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, particularly preferably 2% by mass. It is as follows.

The total content of component (B), component (E), and component (F) is preferably 1% by mass or more, more preferably 1.5% by mass or more, based on 100% by mass of the nonvolatile components of the resin composition. , more preferably 2% by mass or more, preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 5% by mass or less.

<(G) Optional additive>
The resin composition according to one embodiment of the present invention may further contain (G) an arbitrary additive in combination with the above-mentioned components (A) to (F) as an arbitrary component. The optional additives (G) as component (G) do not include those corresponding to components (A) to (F) described above.

(G) Optional additives include, for example, maleimide-based radically polymerizable compounds, vinylphenyl-based radically polymerizable compounds, (meth)acrylic-based radically polymerizable compounds, allyl-based radically polymerizable compounds, and polybutadiene-based radically polymerizable compounds. radical polymerizable compounds such as; radical polymerization initiators such as peroxide radical polymerization initiators and azo radical polymerization initiators; inorganic fillers such as silica particles; organic fillers such as rubber particles; organocopper compounds, organic Organometallic compounds such as zinc compounds; Polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; Leveling agents such as silicone leveling agents and acrylic polymer leveling agents; Thickeners such as bentone and montmorillonite; Silicone antifoaming agents , antifoaming agents such as acrylic antifoaming agents, fluorine antifoaming agents, and vinyl resin antifoaming agents; ultraviolet absorbers such as benzotriazole ultraviolet absorbers; adhesion improvers such as urea silane; triazole adhesion adhesion-imparting agents such as adhesion-imparting agents, tetrazole-based adhesion-imparting agents, and triazine-based adhesion-imparting agents; antioxidants such as hindered phenol-based antioxidants; phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, Flame retardants such as phosphinic acid compounds, red phosphorus), nitrogen flame retardants (e.g. melamine sulfate), halogen flame retardants, inorganic flame retardants (e.g. antimony trioxide); borate stabilizers, titanate stabilizers, aluminates Examples of stabilizers include system stabilizers, zirconate stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, and carboxylic acid anhydride stabilizers. (G) Arbitrary additives may be used alone or in combination of two or more.

<(H) Solvent>
The resin composition may further contain a solvent (H) as a volatile component in addition to the non-volatile components (A) to (G) described above.

As the (H) solvent, an organic solvent is usually used. Examples of the (H) solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. ether ester solvents; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (H) Solvents may be used alone or in combination of two or more.

(H) The amount of the solvent is preferably set so that the melt viscosity of the resin composition can be adjusted to an appropriate range. The amount of the (H) solvent is, for example, 3% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.1% by mass or less, 0.5% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. 0.01% by mass or less. Among these, it is particularly preferable that the resin composition does not contain the (H) solvent. When the amount of the (H) solvent is small, the generation of voids due to the volatilization of the (H) solvent can be suppressed. Furthermore, the handling and workability of the resin composition can be improved.

<Characteristics of resin composition>
The resin composition described above can be cured by heat. Therefore, by thermosetting the resin composition, a cured product of the resin composition can be obtained. Generally, among the components contained in a resin composition, volatile components such as (H) solvent can be volatilized by the heat during thermosetting, but non-volatile components such as components (A) to (G) can be volatile during thermosetting. It does not evaporate due to heat. Therefore, the cured product of the resin composition may contain the nonvolatile components of the resin composition or a reaction product thereof.

According to the resin composition according to the present embodiment, a cured product having low melt viscosity, high relative magnetic permeability, and low magnetic loss can be obtained. Usually, the cured product of the resin composition according to the present embodiment is a cured product of a conventional resin composition containing Fe-Ni alloy magnetic powder that does not contain Si and Cr, and a cured product of a conventional resin composition that contains Fe-Ni-based alloy magnetic powder that does not contain Si and Cr. Melt viscosity is lower than conventional resin compositions containing alloy magnetic powder.

Therefore, the resin composition can provide a cured product with high relative magnetic permeability. For example, when the relative magnetic permeability of the cured product obtained by thermally curing the resin composition at 190°C for 90 minutes is measured at a measurement frequency of 20 MHz and at room temperature of 23°C, the relative magnetic permeability is preferably 23 or more, more preferably 23.5 or more, and particularly preferably 24 or more. There is no particular upper limit to the relative magnetic permeability, and it can be, for example, 35 or less, or 30 or less. The relative magnetic permeability of the cured product can be measured by the method described in the examples below.

Moreover, according to the resin composition, a cured product having low magnetic loss can be obtained. Magnetic loss can be expressed by a loss coefficient tan δ, and usually, the smaller the loss coefficient tan δ is, the smaller the magnetic loss is. For example, when the loss coefficient tan δ of a cured product obtained by thermally curing a resin composition at 190°C for 90 minutes is measured at a measurement frequency of 20 MHz and a room temperature of 23°C, the loss coefficient tan δ is preferably 0.04 or less, and more preferably 0.04 or less. It is preferably 0.038 or less, particularly preferably 0.035 or less. The lower limit of the loss coefficient is not particularly limited, and may be, for example, 0.00001 or more. The loss coefficient tan δ of the cured product can be measured by the method described in the Examples below.

The resin composition described above exhibits a characteristic of low melt viscosity. Therefore, it becomes possible to easily fill the holes with the resin composition without dissolving the resin composition with a solvent or the like. The melt viscosity is preferably 30,000 poise or less, more preferably 25,000 poise or less, even more preferably 23,000 poise or less. The upper limit is not particularly limited, and may be, for example, 100 poise or more. Melt viscosity can be measured by the method described in Examples below.

Crystalline alloy powders, such as alloy powders containing Fe and Ni, can generally have high relative magnetic permeability, but tend to have large magnetic losses. Furthermore, the melt viscosity tended to increase. Therefore, conventionally, it has been difficult to obtain a cured product of a resin composition that has a low melt viscosity, a high relative magnetic permeability, and a small magnetic loss. In view of such conventional circumstances, the effects of the present invention are industrially beneficial.

There are no particular restrictions on the properties of the resin composition. Therefore, the resin composition may be in the form of a solid or a fluid paste. For example, the resin composition may be made into a paste-like resin composition using a solvent, or it may be made into a paste-like resin composition that does not contain a solvent by using a liquid thermosetting resin such as a liquid epoxy resin. You can also use it as When the content of the solvent in the resin composition is small or when the resin composition does not contain a solvent, it is possible to suppress the generation of voids due to the volatilization of the solvent, and it also has excellent handling and workability. be able to.

The resin composition is preferably used as a resin composition for manufacturing an inductor by taking advantage of the above-mentioned excellent properties. For example, the resin composition described above is preferably used as a hole-filling resin composition for filling holes in a circuit board. Further, for example, the resin composition described above is also preferably used to form a cured material layer on a circuit board. In order to facilitate application to these uses, the resin composition may be used in the form of a paste or in the form of a resin sheet containing a layer of the resin composition.

<Method for manufacturing resin composition>
The resin composition according to one embodiment of the present invention can be manufactured, for example, by mixing the above-mentioned components. The above-mentioned components may be mixed in part or in whole at the same time, or in order. During the process of mixing each component, the temperature may be set as appropriate, and thus may be heated and/or cooled temporarily or throughout. Moreover, in the process of mixing each component, stirring or shaking may be performed. Furthermore, defoaming may be performed under low pressure conditions such as under vacuum.

<Magnetic paste>
A magnetic paste according to one embodiment of the present invention includes the resin composition described above. Since magnetic paste is usually a fluid paste containing a resin composition, it can be preferably used for filling holes by printing. This magnetic paste may contain only the above-mentioned resin composition, or may contain arbitrary components in combination with the resin composition. Preferably, the paste-like resin composition itself can be used as the magnetic paste.

The magnetic paste is preferably in a paste form at 23°C. The viscosity of this magnetic paste at 23°C is preferably 20 Pa·s or more, more preferably 25 Pa·s or more, even more preferably 30 Pa·s or more, and particularly preferably 50 Pa·s or more, and is preferably 200 Pa·s or less, more preferably 180 Pa·s or less, and even more preferably 160 Pa·s or less. The viscosity can be measured, for example, using an E-type viscometer (Toki Sangyo Co., Ltd. "RE-80U", 3° x R9.7 rotor) under measurement conditions of a measurement sample volume of 0.22 ml and a rotation speed of 5 rpm.

<Resin sheet>
A resin sheet according to one embodiment of the present invention includes a support and a resin composition layer provided on the support. The resin composition layer contains the resin composition described above, and preferably contains only the resin composition.

From the viewpoint of thinning, the thickness of the resin composition layer is preferably 250 μm or less, more preferably 200 μm or less. The lower limit of the thickness of the resin composition layer may be, for example, 5 μm or more, 10 μm or more, etc.

Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

When a film of plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"). ), polyesters such as polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylic polymers such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When using metal foil as the support, examples of the metal foil include copper foil, aluminum foil, etc., with copper foil being preferred. As the copper foil, a foil made of a single metal such as copper may be used, or a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. May be used.

The support may be subjected to matte treatment or corona treatment on the surface to be bonded to the resin composition layer.

As the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd-based release agents, polyolefin-based release agents, urethane-based release agents, and silicone-based release agents. The support with a release layer may be a commercially available product, and examples thereof include "PET501010", "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation, which are PET films having a release layer mainly composed of a silicone-based release agent or an alkyd resin-based release agent; "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin Limited; and "Unipeel" manufactured by Unitika Limited.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. In addition, when using the support body with a mold release layer, it is preferable that the thickness of the whole support body with a mold release layer is in the said range.

In the resin sheet, a protective film similar to the support may be provided on the surface of the resin composition layer that is not bonded to the support (that is, the surface opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By providing the protective film, it is possible to suppress the adhesion of dust and the like to the surface of the resin composition layer and to prevent scratches.

The resin sheet can be manufactured, for example, by applying a resin composition onto a support using a die coater or the like to form a resin composition layer. If necessary, the resin composition may be mixed with an organic solvent and then applied onto the support. When using an organic solvent, drying may be performed after coating, if necessary.

Drying may be performed, for example, by heating, blowing hot air, or the like. The drying conditions are not particularly limited, but the resin composition layer is dried so that the content of the organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. A resin composition layer can be formed by drying at 50° C. to 150° C. for 3 minutes to 10 minutes, although it varies depending on the components contained in the resin composition.

The resin sheet can be stored by winding it up into a roll. When the resin sheet has a protective film, it can usually be used by peeling off the protective film.

<Circuit board and its manufacturing method>
The circuit board includes a cured product of the resin composition described above. The specific structure of the circuit board is not limited as long as it includes a cured product of the resin composition. The circuit board according to the first example includes a substrate having holes and a cured resin composition filled in the holes. Further, the circuit board according to the second example includes a cured product layer containing a cured product of the resin composition. Hereinafter, methods for manufacturing circuit boards according to these first and second examples will be explained. However, the circuit board and its manufacturing method are not limited to the first example and second example illustrated below.

<Circuit board according to first example>
The circuit board according to the first example includes a substrate in which a hole is formed, and a cured product of a resin composition filled in the hole. This circuit board is, for example,
(1) Filling the holes in the substrate with a resin composition, and
(2) a step of thermally curing the resin composition to obtain a cured product;
It can be manufactured by a manufacturing method including. Further, the method for manufacturing a circuit board according to the first example further includes:
(3) a step of polishing the surface of the cured product or the resin composition; (4) a step of roughening the cured product; and
(5) forming a conductor layer on the cured product;
May contain. Usually, the above steps (1) to (5) may be performed in the order of step (1), step (2), step (3), step (4) and step (5), and step (3) Step (2) may be performed after. In the method for manufacturing a circuit board according to the first example, it is preferable to form a cured product using a paste-like resin composition. In the following description, an example will be described using a substrate in which a through hole is formed as a hole passing through the substrate in the thickness direction.

<Step (1)>
Step (1) usually includes the step of preparing a substrate in which through holes are formed. The substrate may be purchased and prepared from the market. Additionally, the substrate may be manufactured and provided using any suitable material. Hereinafter, a method for manufacturing a substrate according to an example will be described.

FIG. 1 is a cross-sectional view schematically showing a core substrate 10 prepared in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. The step of preparing the substrate may include the step of preparing the core substrate 10, as in the example shown in FIG. Core substrate 10 typically includes support substrate 11 . Examples of the support substrate 11 include insulating substrates such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. Furthermore, a metal layer may be provided on the support substrate 11. The metal layer may be provided on one side of the support substrate 11, or may be provided on both sides. Here, an example is shown in which metal layers 12 and 13 are provided on both surfaces of the support substrate 11. Examples of the metal layers 12 and 13 include layers made of metal such as copper. The metal layers 12 and 13 may be, for example, a copper foil such as a copper foil with a carrier, or may be a metal layer formed of a material for a conductor layer to be described later.

FIG. 2 is a cross-sectional view schematically showing a core substrate 10 in which through holes 14 are formed in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. The step of preparing the substrate may include the step of forming through holes 14 in the core substrate 10, as in the example shown in FIG. The through hole 14 can be formed by, for example, drilling, laser irradiation, plasma irradiation, or the like. Usually, the through hole 14 can be formed by forming a through hole in the core substrate 10. For example, the through holes 14 can be formed using a commercially available drill device. Commercially available drill devices include, for example, "ND-1S211" manufactured by Hitachi Via Mechanics.

FIG. 3 is a cross-sectional view schematically showing a core substrate 10 in which a plating layer 20 is formed in a through hole 14 in a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. The step of preparing the substrate may include a step of forming a plating layer 20 as shown in FIG. 3 after roughening the core substrate 10 as necessary. As the roughening treatment, either dry or wet roughening treatment may be performed. Examples of dry roughening treatment include plasma treatment and the like. Furthermore, an example of the wet roughening treatment includes a method in which a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid are performed in this order. Plating layer 20 may be formed by a plating method. The procedure for forming the plating layer 20 by the plating method may be the same as the formation of the conductor layer in step (5) described later. Here, an example will be described in which the plating layer 20 is formed inside the through hole 14, on the surface of the metal layer 12, and on the surface of the metal layer 13.

FIG. 4 is a cross-sectional view schematically showing how the through-holes of the core substrate 10 are filled with the resin composition 30a in the method for manufacturing a circuit board according to the first example of the embodiment of the present invention. In step (1), after preparing the core substrate 10 in which the through holes 14 are formed as described above, as shown in FIG. 4, the through holes 14 of the core substrate 10 are filled with a resin composition 30a. including. Filling can be carried out, for example, by a printing method. Examples of printing methods include, for example, a method of printing the resin composition 30a into the through hole 14 via a squeegee, a method of printing the resin composition 30a via a cartridge, a method of printing the resin composition 30a by mask printing, Examples include a roll coating method and an inkjet method.

<Step (2)>
FIG. 5 is a schematic cross-sectional view for explaining step (2) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. Step (2) includes filling the through hole 14 with the resin composition 30a and then curing the resin composition 30a to form a cured product 30 as shown in FIG.

The resin composition 30a is usually cured by heat curing. The thermosetting conditions for the resin composition 30a can be appropriately set within a range that allows the resin composition 30a to proceed with curing. The curing temperature is preferably 120°C or higher, more preferably 130°C or higher, even more preferably 150°C or higher, and preferably 245°C or lower, more preferably 220°C or lower, and still more preferably 200°C or lower. The curing time is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, and preferably 120 minutes or less, more preferably 110 minutes or less, and still more preferably 100 minutes or less.

The degree of curing of the cured product 30 obtained in step (2) is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. The degree of curing can be measured using, for example, a differential scanning calorimeter.

The method for manufacturing a circuit board according to the first example includes heating the resin composition 30a at a temperature lower than the curing temperature after filling the resin composition 30a into the through holes 14 and before curing the resin composition 30a. It may include a step (preheating step). For example, before curing the resin composition 30a, the resin composition 30a is usually cured at a temperature of 50°C or higher and lower than 120°C (preferably 60°C or higher and 110°C or lower, more preferably 70°C or higher and 100°C or lower). , usually for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes).

<Step (3)>
FIG. 6 is a schematic cross-sectional view for explaining step (3) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. When the resin composition 30a is filled into the through hole 14 in step (1), the excess resin composition 30a may protrude or adhere to the outside of the through hole 14. Therefore, the resin composition 30a can be provided not only inside the through hole 14 but also outside the through hole 14. Therefore, step (3) includes polishing the excess cured material 30 protruding from or adhering to the core substrate 10, as shown in FIG. By polishing, excess cured product 30 is removed, so the surface of cured product 30 can be flattened. Further, the surface (polished surface) 31 of the cured product 30 that has been flattened by polishing is usually flush with the surrounding surface 21 (for example, the surface of the core substrate 10 or the surface of the plating layer 20). A plane can be formed.

As a method of polishing the cured product 30, a method that can remove excess cured product 30 protruding from or attached to the core substrate 10 can be adopted. Examples of such polishing methods include buff polishing, belt polishing, ceramic polishing, and the like. Commercially available buffing devices include, for example, "NT-700IM" manufactured by Ishii Hyoki Co., Ltd.

The arithmetic mean roughness (Ra) of the polished surface 31 (surface after curing) of the cured product 30 is preferably 300 nm or more, more preferably 350 nm or more, from the viewpoint of improving the adhesion with the conductor layer. Preferably it is 400 nm or more. The upper limit is preferably 1000 nm or less, more preferably 900 nm or less, even more preferably 800 nm or less. Surface roughness (Ra) can be measured using, for example, a non-contact surface roughness meter.

The method for manufacturing a circuit board according to the first example may include, after step (3), a step of subjecting the cured product 30 to a heat treatment in order to further increase the degree of curing of the cured product 30. The temperature in the heat treatment can be similar to the curing temperature described above. The specific heat treatment temperature is preferably 120°C or higher, more preferably 130°C or higher, even more preferably 150°C or higher, and preferably 245°C or lower, more preferably 220°C or lower, and still more preferably 200°C or lower. . The heat treatment time is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, and preferably 90 minutes or less, more preferably 70 minutes or less, and still more preferably 60 minutes or less.

Furthermore, when step (3) is performed before step (2), a preliminary heat treatment may be performed in which the resin composition is heated at a temperature lower than the curing temperature of the resin composition. The temperature in the preheating treatment is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, preferably 245°C or lower, more preferably 220°C or lower, even more preferably 200°C or lower. be. The heat treatment time is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, and preferably 90 minutes or less, more preferably 70 minutes or less, and still more preferably 60 minutes or less.

<Step (4)>
Step (4) includes subjecting the cured product 30 to roughening treatment (desmear treatment). The surface of the cured product 30 is roughened by the roughening treatment. When the surface of the cured product 30 is polished, it usually includes performing a roughening treatment (desmear treatment) on the polished surface 31. The procedure and conditions for the roughening treatment are not particularly limited, and, for example, procedures and conditions used in a method for manufacturing a multilayer printed wiring board can be adopted. To give a specific example, the cured product 30 can be roughened by performing swelling treatment with a swelling liquid, roughening treatment with an oxidizing agent, and neutralization treatment with a neutralizing liquid in this order.

Examples of the swelling liquid that can be used in the roughening step include alkaline solutions, surfactant solutions, etc., and preferably alkaline solutions. As the alkaline solution which is the swelling liquid, sodium hydroxide solution and potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan.

The swelling treatment with a swelling liquid can be performed, for example, by immersing the cured product 30 in a swelling liquid at 30° C. to 90° C. for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin contained in the cured product 30 to an appropriate level, it is preferable to immerse the cured product 30 in a swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes.

Examples of the oxidizing agent that can be used in the roughening treatment with an oxidizing agent include an alkaline permanganic acid solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the cured product 30 in a solution of the oxidizing agent heated to 60° C. to 80° C. for 10 minutes to 30 minutes. Further, the concentration of permanganate in the alkaline permanganic acid solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact P" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

As the neutralizing liquid that can be used for the neutralization treatment, an acidic aqueous solution is preferable. Examples of commercially available neutralizing liquids include "Reduction Solution Securigance P" manufactured by Atotech Japan. The neutralization treatment with a neutralizing liquid can be carried out by immersing the treated surface that has been roughened with an oxidizing agent solution in the neutralizing liquid at 30° C. to 80° C. for 5 minutes to 30 minutes. From the viewpoint of workability, etc., it is preferable to immerse the cured product 30, which has been roughened with an oxidizing agent solution, in a neutralizing solution at 40° C. to 70° C. for 5 minutes to 20 minutes.

The arithmetic mean roughness (Ra) of the surface of the cured product 30 after the roughening treatment is preferably 300 nm or more, more preferably 350 nm or more, and even more preferably 400 nm, from the viewpoint of improving the adhesion with the conductor layer. That's all. The upper limit is preferably 1500 nm or less, more preferably 1200 nm or less, even more preferably 1000 nm or less. Surface roughness (Ra) can be measured using, for example, a non-contact surface roughness meter.

<Step (5)>
FIG. 7 is a schematic cross-sectional view for explaining step (5) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. Step (5) includes forming a conductor layer 40 on the polished surface 31 of the cured product 30, as shown in FIG. Here, an example is shown in which the conductor layer 40 is formed not only on the polished surface 31 of the cured product 30 but also on the surrounding surface 21 (for example, the surface of the core substrate 10 and the surface of the plating layer 20). Further, although FIG. 7 shows an example in which the conductor layer 40 is formed on both sides of the core substrate 10, the conductor layer 40 may be formed only on one side of the core substrate 10.

FIG. 8 is a schematic cross-sectional view for explaining step (5) of a method for manufacturing a circuit board according to a first example of an embodiment of the present invention. As shown in FIG. 8, in step (5), after forming the conductor layer 40, parts of the conductor layer 40, the metal layer 12, the metal layer 13, and the plating layer 20 are removed by a process such as etching. , may include forming a patterned conductor layer 41.

Examples of methods for forming the conductor layer 40 include plating, sputtering, and vapor deposition, with plating being preferred. In a preferred embodiment, a patterned conductor layer 41 having a desired wiring pattern can be formed by plating the surface of the cured product 30 (and plating layer 20) by an appropriate method such as a semi-additive method or a fully additive method. Examples of the material for the conductor layer 40 include single metals such as gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium; gold, platinum, palladium, Examples include alloys of two or more metals selected from the group of silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. Among them, chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, nickel-chromium alloy, copper-nickel alloy, copper-titanium alloy can be used from the viewpoint of versatility, cost, ease of patterning, etc. Preferably, chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy is used, and copper is even more preferably used.

Here, an example of a method for forming the patterned conductor layer 41 on the polished surface 31 of the cured product 30 will be described in detail. A plating seed layer is formed on the polished surface 31 of the cured product 30 by electroless plating. Next, an electrolytic plating layer is formed on the formed plating seed layer by electrolytic plating. Thereafter, if necessary, unnecessary plating seed layers can be removed by a process such as etching to form a patterned conductor layer 41 having a desired wiring pattern. After forming the patterned conductor layer 41, an annealing treatment may be performed as necessary to improve the adhesion strength of the patterned conductor layer 41. The annealing treatment can be performed, for example, by heating at 150 to 200° C. for 20 to 90 minutes.

From the viewpoint of thinning, the thickness of the patterned conductor layer 41 is preferably 70 μm or less, more preferably 60 μm or less, even more preferably 50 μm or less, even more preferably 40 μm or less, particularly preferably 30 μm or less, 20 μm or less, 15 μm or less. Or it is 10 μm or less. The lower limit is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more.

By the above method, a circuit board 1 including a cured product 30 of the resin composition 30a can be manufactured.

<Circuit board according to second example>
The circuit board according to the second example includes a cured product layer containing a cured product of the resin composition. The cured product layer preferably contains only the cured product of the resin composition. The cured material layer is preferably formed using a resin sheet. This circuit board is, for example,
(i) forming a cured material layer on the inner layer substrate;
(ii) a step of drilling holes in the cured material layer;
(iii) a step of roughening the surface of the cured material layer; and (iv) a step of forming a conductor layer on the surface of the cured material layer;
It can be manufactured by a manufacturing method including.

<Step (i)>
Step (i) includes forming a cured material layer on the inner layer substrate. Preferably, step (i) includes laminating the resin sheet on the inner layer substrate so that the resin composition layer is bonded to the inner layer substrate to form a cured material layer. For example, a resin sheet is laminated on an inner layer substrate so that the resin composition layer is bonded to the inner layer substrate, and the resin composition layer is thermally cured to form a cured material layer.

Figure 9 is a schematic cross-sectional view for explaining step (i) in a method for manufacturing a circuit board according to a second example of one embodiment of the present invention. As shown in Figure 9, a resin sheet 310 is prepared, which includes a support 330 and a resin composition layer 320a provided on the support 330. Then, the resin sheet 310 and the inner layer substrate 200 are laminated together so that the resin composition layer 320a is bonded to the inner layer substrate 200.

As the inner layer substrate 200, an insulating substrate can be used. Examples of the inner layer substrate 200 include insulating substrates such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. The inner layer board 200 may be an inner layer circuit board in which wiring and the like are built into its thickness.

Inner layer substrate 200 shown in this example includes a first conductor layer 420 provided on first main surface 200a and external terminal 240 provided on second main surface 200b. The first conductor layer 420 may include a plurality of wires. However, in the example shown in FIG. 9, only the wiring that constitutes the coiled conductive structure 400 (see FIG. 12) of the inductor element is shown. The external terminal 240 may be a terminal for electrically connecting to an external device (not shown) or the like. External terminal 240 can be configured as part of a conductor layer provided on second main surface 200b.

Examples of the conductor material that can constitute the first conductor layer 420 and the external terminal 240 include the same materials as the conductor layer described in the first example.

The first conductor layer 420 and the external terminal 240 may have a single layer structure, or may have a multilayer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. Further, the thickness of the first conductor layer 420 and the external terminal 240 may be the same as that of a second conductor layer 440, which will be described later.

The line (L)/space (S) ratio of the first conductor layer 420 and the external terminal 240 is not particularly limited, but from the viewpoint of reducing surface irregularities and obtaining a cured layer with excellent smoothness, it is usually 900/900 μm or less, preferably 700/700 μm or less, more preferably 500/500 μm or less, even more preferably 300/300 μm or less, and even more preferably 200/200 μm or less. The lower limit of the line/space ratio is not particularly limited, but from the viewpoint of improving the embedding of the resin composition layer in the space, it is preferably 1/1 μm or more.

Inner layer substrate 200 may have a plurality of through holes 220 that penetrate inner layer substrate 200 from first main surface 200a to second main surface 200b. The through hole 220 is provided with an in-through hole wiring 220a. The through-hole wiring 220a electrically connects the first conductor layer 420 and the external terminal 240.

The resin composition layer 320a and the inner substrate 200 can be bonded, for example, by heat-pressing the resin sheet 310 to the inner substrate 200 from the support 330 side. Examples of the member for heat-pressing the resin sheet 310 to the inner layer substrate 200 (hereinafter also referred to as "heat-pressing member") include a heated metal plate (stainless steel (SUS) end plate, etc.), a metal roll (SUS roll), etc. can be mentioned. Note that instead of pressing the thermocompression bonding member in direct contact with the resin sheet 310, a sheet made of an elastic material such as heat-resistant rubber or the like is used so that the resin sheet 310 sufficiently follows the unevenness of the surface of the inner layer substrate 200. It is preferable to press through the .

The temperature during heat-pressure bonding is preferably in the range of 80°C to 160°C, more preferably 90°C to 140°C, and even more preferably 100°C to 120°C, the pressure during heat-pressure bonding is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the time during heat-pressure bonding is preferably in the range of 20 seconds to 400 seconds, and more preferably 30 seconds to 300 seconds. The resin sheet and the inner layer substrate are preferably bonded under reduced pressure conditions of 26.7hPa or less.

The resin composition layer 320a of the resin sheet 310 and the inner layer substrate 200 can be bonded using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressurized laminator manufactured by Meiki Seisakusho, and a vacuum applicator manufactured by Nikko Materials.

After the resin sheet 310 and the inner layer substrate 200 are bonded, the laminated resin sheets 310 are smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression bonding member from the support body 330 side. Good too. The pressing conditions for the smoothing treatment can be the same as the conditions for the heat-pressing of the lamination described above. The smoothing process can be performed using a commercially available laminator. Note that the lamination and smoothing treatment may be performed continuously using the above-mentioned commercially available vacuum laminator.

FIG. 10 is a schematic cross-sectional view for explaining step (i) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. After laminating the resin sheet 310 on the inner layer substrate 200, the resin composition layer 320a is cured to form a cured material layer. In this example, as shown in FIG. 10, the resin composition layer 320a bonded to the inner layer substrate 200 is thermally cured to form a first cured material layer 320.

Thermal curing conditions for the resin composition layer 320a can be appropriately set within a range in which curing of the resin composition proceeds. The curing temperature is preferably 120°C or higher, more preferably 130°C or higher, even more preferably 150°C or higher, and preferably 245°C or lower, more preferably 220°C or lower, and still more preferably 200°C or lower. The curing time is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 15 minutes or more, and preferably 120 minutes or less, more preferably 110 minutes or less, and even more preferably 100 minutes or less.

The support 330 may be removed between after heat curing in step (i) and step (ii), or may be peeled off after step (ii).

The arithmetic mean roughness (Ra) of the cured material layer before roughening treatment is preferably 300 nm or more, more preferably 350 nm or more, and even more preferably 400 nm or more, from the viewpoint of improving the adhesion with the plating. . The upper limit is preferably 1000 nm or less, more preferably 900 nm or less, even more preferably 800 nm or less. Surface roughness (Ra) can be measured using, for example, a non-contact surface roughness meter.

In step (i), instead of using a resin sheet, a resin composition may be applied onto the inner layer substrate 200 using a die coater or the like, and the resin composition may be thermally cured to form a cured material layer.

<Step (ii)>
FIG. 11 is a schematic cross-sectional view for explaining step (ii) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. Step (ii) includes drilling a hole in the first cured material layer 320 to form a via hole 360, as shown in FIG. The via hole 360 forms a path for electrically connecting the first conductor layer 420 and a second conductor layer 440, which will be described later. The via hole 360 may be formed using, for example, a drill, laser, plasma, or the like. The size and shape of the hole may be determined as appropriate depending on the design of the printed wiring board.

<Step (iii)>
In step (iii), the surface of the cured material layer in which the via holes are formed is roughened. The roughening treatment in step (iii) can be performed in the same manner as described in step (4) of the first example.

From the viewpoint of improving adhesion with the plating, the arithmetic mean roughness (Ra) of the cured layer after roughening treatment is preferably 300 nm or more, more preferably 350 nm or more, and even more preferably 400 nm or more. The upper limit is preferably 1500 nm or less, more preferably 1200 nm or less, and even more preferably 1000 nm or less. The surface roughness (Ra) can be measured, for example, using a non-contact surface roughness meter.

<Step (iv)>
FIG. 12 is a schematic cross-sectional view for explaining step (iv) in a method for manufacturing a circuit board according to a second example of an embodiment of the present invention. As shown in FIG. 12, in step (iv), a second conductor layer 440 is formed on the first cured material layer 320.

Examples of the conductive material that can constitute the second conductive layer 440 include the same material as the conductive layer described in the first example.

From the viewpoint of thinning, the thickness of the second conductor layer 440 is preferably 70 μm or less, more preferably 60 μm or less, even more preferably 50 μm or less, even more preferably 40 μm or less, particularly preferably 30 μm or less, 20 μm or less, or 15 μm or less. or less than or equal to 10 μm. The lower limit is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more.

The second conductor layer 440 can be formed by plating. The second conductor layer 440 is preferably formed by a wet plating method such as a semi-additive method or a full-additive method including, for example, an electroless plating process, a mask pattern forming process, an electrolytic plating process, and a flash etching process. By forming the second conductor layer 440 using a wet plating method, it is possible to form the second conductor layer 440 including a desired wiring pattern. Note that via this step, an in-via hole wiring 360a is also formed in the via hole 360.

The first conductor layer 420 and the second conductor layer 440 may be provided in a spiral shape, for example, as shown in FIGS. 13 to 15, which will be described later. In one example, one end of the spiral wiring portion of the second conductor layer 440 on the center side is electrically connected to one end of the spiral wiring portion of the first conductor layer 420 on the center side by the via hole wiring 360a. has been done. The other end of the spiral wiring portion of the second conductor layer 440 on the outer peripheral side is electrically connected to the land 420a of the first conductor layer 420 by a via hole wiring 360a. Therefore, the other end on the outer peripheral side of the spiral wiring portion of the second conductor layer 440 is electrically connected to the external terminal 240 via the via hole wiring 360a, the land 420a, and the through hole wiring 220a.

The coil-shaped conductive structure 400 is composed of a spiral wiring portion that is part of the first conductor layer 420, a spiral wiring portion that is part of the second conductor layer 440, and via-hole wiring 360a that electrically connects the spiral wiring portion of the first conductor layer 420 and the spiral wiring portion of the second conductor layer 440.

After step (iv), a step of forming a cured material layer on the conductor layer may be further performed. In detail, as an example is shown in FIG. 14, the second cured material layer 340 is formed on the first cured material layer 320 on which the second conductor layer 440 and the via hole wiring 360a are formed. The second cured material layer may be formed by the same steps as those already described. By the above method, the circuit board 100 including the first cured material layer 320 and the second cured material layer 340 formed of the cured product of the resin composition can be manufactured.

<Inductor board>
The inductor board includes the circuit board described above. When such an inductor board includes a circuit board obtained by the method for manufacturing a circuit board according to the first example described above, an inductor pattern formed of a conductor on at least a part of the periphery of the cured resin composition is used. It can have In this case, the inductor substrate is formed of, for example, an inductor pattern formed of at least a portion of the metal layer 12, the metal layer 13, the plating layer 20, and the patterned conductor layer 41, and the cured material 30 surrounded by the inductor pattern. The inductor element may include an inductor element configured by a core portion. As such an inductor substrate, for example, the one described in Japanese Patent Application Publication No. 2016-197624 can be applied.

Further, when including a circuit board obtained by the method for manufacturing a circuit board according to the second example, the inductor board includes a cured material layer and a conductive structure at least partially embedded in the cured material layer. I can do it. The inductor substrate includes an inductor element configured by a conductive structure and a portion of the cured material layer that extends in the thickness direction of the cured material layer and is surrounded by the conductive structure. sell.

FIG. 13 is a schematic plan view of the circuit board 100 included in the inductor board, viewed from one side in the thickness direction. FIG. 14 is a schematic view showing a cut end surface of the circuit board 100 cut at the position indicated by the dashed line II-II shown in FIG. FIG. 15 is a schematic plan view for explaining the configuration of the first conductor layer 420 of the circuit board 100 included in the inductor board.

As shown in FIGS. 13 and 14 as an example, the circuit board 100 includes a plurality of cured material layers (first cured material layer 320, second cured material layer 340) and a plurality of conductor layers (first conductor layer 420, The second conductive layer 440) may be a substrate having a second conductive layer 440). Therefore, in the example shown here, the circuit board 100 may be a build-up wiring board having a build-up cured material layer and a build-up conductor layer. Further, the circuit board 100 includes an inner layer board 200.

As shown in FIG. 14, the first cured material layer 320 and the second cured material layer 340 constitute a magnetic section 300 that can be viewed as an integrated cured material layer. Therefore, the coiled conductive structure 400 is provided so that at least a portion thereof is embedded in the magnetic part 300. That is, in the circuit board 100 shown in this example, the inductor element includes the coiled conductive structure 400 and the magnetic section 300 that extends in the thickness direction of the magnetic section 300 and is surrounded by the coiled conductive structure 400. It is made up of a core that is a part of the core.

As shown in FIG. 15 as an example, the first conductor layer 420 includes a spiral wiring part for configuring the coiled conductive structure 400 and a rectangular wiring part electrically connected to the through-hole wiring 220a. and a land 420a. In the example shown here, the spiral wiring portion includes a bent portion that is bent at right angles to the straight portion and a detour portion that detours around the land 420a. Further, the spiral wiring portion of the first conductor layer 420 has a generally rectangular outline, and has a shape that is wound counterclockwise from the center side toward the outside.

Similarly, a second conductor layer 440 is provided on the first cured material layer 320. The second conductor layer 440 includes a spiral wiring portion for forming the coiled conductive structure 400 . In FIG. 13 or 14, the spiral wiring portion includes a straight portion and a bent portion bent at right angles. In FIG. 13 or 14, the spiral wiring portion of the second conductor layer 44 has a substantially rectangular overall outline, and has a shape that is wound clockwise from the center toward the outside.

The above-described inductor substrate can be used as a wiring board for mounting electronic components such as semiconductor chips, and can also be used as a (multilayer) printed wiring board using such a wiring board as an inner layer board. Moreover, such a wiring board can be used as a chip inductor component made into individual pieces, and the chip inductor component can also be used as a surface-mounted printed wiring board.

Furthermore, various types of semiconductor devices can be manufactured using such a wiring board. Semiconductor devices including such wiring boards can be suitably used in electrical products (e.g., computers, mobile phones, digital cameras, televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.). .

The present invention will be specifically explained below with reference to examples. The present invention is not limited to these examples. In the following, "%" and "parts" representing amounts mean "% by mass" and "parts by mass" unless otherwise specified. Furthermore, unless a temperature is specifically specified, the temperature condition is room temperature (23°C). Furthermore, unless a pressure is specifically specified, the pressure condition is normal pressure (1 atm).

<Example 1: Production of varnish-like resin composition 1>
Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-1Si-3Cr", alloy of 50% Fe, 46% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true ^150.0 parts by mass of magnetic powder (“MZ03S” manufactured by Powder Tech Co., Ltd., Mn-Zn ferrite powder, average particle diameter (D ₅₀ ) 0.5 μm, true density 5.1 g /cm ³ ), 30.0 parts by mass of epoxy resin (ZX-1059 manufactured by Nippon Steel Chemical & Materials, a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, epoxy equivalent 169 g/eq., true Density 1.2 g/cm ³ ) 3.7 parts by mass, phenol resin (DIC "LA-7054", aminotriazine modified phenol novolak resin, MEK solution with 60% non-volatile components, hydroxyl equivalent 125 g/eq., non-volatile) 4.2 parts by mass of true density of 1.2 g/cm ³ ), phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation, a solution of methyl ethyl ketone: cyclohexanone = 1:1 with 30% nonvolatile components, special skeleton phenoxy resin, 1.1 parts by mass of nonvolatile components (true density 1.2 g/cm ³ ), 0 dispersant (PB-881 manufactured by Ajinomoto Fine Techno, polyester dispersant, true density 1.2 g/cm ³ ) .8 parts by mass, 0.1 parts by mass of a curing accelerator (“2E4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd., imidazole curing accelerator, true density 1.2 g/cm ³ ), and 6.7 parts by mass of a solvent (methyl ethyl ketone). A varnish-like resin composition 1 was prepared by uniformly dispersing the resin composition.

<Example 2: Preparation of varnish-like resin composition 2>
In Example 1,
1) Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-1Si-3Cr", alloy of 50% Fe, 46% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm , true density 8.0 g/cm ³ ) was changed from 150.0 parts by mass to 133.6 parts by mass,
2) The amount of magnetic powder (“MZ03S” manufactured by Powder Tech, Mn-Zn ferrite powder, average particle diameter (D ₅₀ ) 0.5 μm, true density 5.1 g/cm ³ ) was 30.0 parts by mass. The amount was changed from 40.0 parts by mass.
Varnish-like resin composition 2 was prepared in the same manner as in Example 1 except for the above matters.

<Example 3: Preparation of varnish-like resin composition 3>
In Example 1,
1) Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-1Si-3Cr", alloy of 50% Fe, 46% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm , true density 8.0 g/cm ³ ) was changed from 150.0 parts by mass to 116.1 parts by mass,
2) The amount of magnetic powder (“MZ03S” manufactured by Powder Tech, Mn-Zn ferrite powder, average particle diameter (D ₅₀ ) 0.5 μm, true density 5.1 g/cm ³ ) was 30.0 parts by mass. The amount was changed from 51.4 parts by mass.
Varnish-like resin composition 3 was prepared in the same manner as in Example 1 except for the above matters.

<Example 4: Preparation of varnish-like resin composition 4>
In Example 1,
1) Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-1Si-3Cr", alloy of 50% Fe, 46% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm , true density 8.0 g/cm ³ ) was changed from 150.0 parts by mass to 98.3 parts by mass,
2) The amount of magnetic powder (“MZ03S” manufactured by Powder Tech, Mn-Zn ferrite powder, average particle diameter (D ₅₀ ) 0.5 μm, true density 5.1 g/cm ³ ) was 30.0 parts by mass. The amount was changed from 61.7 parts by mass.
Varnish-like resin composition 4 was prepared in the same manner as in Example 1 except for the above matters.

<Example 5: Preparation of varnish-like resin composition 5>
In Example 2, 40.0 parts by mass of magnetic powder ("MZ03S" manufactured by Powder Tech, Mn-Zn ferrite powder, average particle size (D ₅₀ ) 0.5 μm, true density 5.1 g/cm ³ ) was used. , magnetic powder ("M03S" manufactured by Powder Tech Co., Ltd., Mn-based ferrite powder, average particle diameter (D ₅₀ ) 0.5 μm, true density 5.0 g/cm ³ ) was changed to 40.0 parts by mass.
Varnish-like resin composition 5 was prepared in the same manner as in Example 2 except for the above matters.

<Example 6: Preparation of varnish-like resin composition 6>
In Example 2, Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass of Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-3Si-4Cr", Fe47%, Ni46 %, Si 3%, Cr 4% alloy, average grain size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass.
Varnish-like resin composition 6 was prepared in the same manner as in Example 2 except for the above matters.

<Example 7: Preparation of varnish-like resin composition 7>
In Example 2, Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass of Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-0.2Si-3Cr", Fe50. 8%, Ni 46%, Si 0.2%, Cr 3% alloy, average grain size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass.
Varnish-like resin composition 7 was prepared in the same manner as in Example 2 except for the above matters.

<Example 8: Preparation of varnish-like resin composition 8>
In Example 2, Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass of Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-1Si-1Cr", Fe52%, Ni46 %, Si 1.0%, Cr 1.0% alloy, average grain size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass.
Varnish-like resin composition 8 was prepared in the same manner as in Example 2 except for the above matters.

<Example 9: Preparation of varnish-like resin composition 9>
In Example 2, Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass of Fe-Ni-Si-Cr alloy magnetic powder (Mitsubishi Steel Corporation "AKT-PB-1Si-6Cr", Fe47%, Ni46 %, Si 1.0%, Cr 6.0% alloy, average grain size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass.
Varnish-like resin composition 9 was prepared in the same manner as in Example 2 except for the above matters.

Comparative Example 1: Preparation of varnish-like resin composition 10
In Example 2, 133.6 parts by mass of Fe-Ni-Si-Cr alloy magnetic powder ("AKT-PB-1Si-3Cr" manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size ( _D50 ) 5 μm, true density 8.0 g/ ^cm3 ) was changed to 133.6 parts by mass of Fe-Ni-Si-Cr alloy magnetic powder ("AKT-PB-1Si-8Cr" manufactured by Mitsubishi Steel Corporation, alloy of 45% Fe, 46% Ni, 1.0% Si, 8.0% Cr, average particle size ( _D50 ) 5 μm, true density 8.0 g/ ^cm3 ).
A varnish-like resin composition 10 was prepared in the same manner as in Example 2 except for the above.

<Comparative Example 2: Preparation of varnish-like resin composition 11>
In Example 2, Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass, Fe-Ni-Si alloy magnetic powder (Epson Atomics "50FE50%NI PF-5F", Fe49%, Ni50%, It was changed to an alloy containing 0.4% Si, an average grain size (D ₅₀ ) of 5 μm, and a true density of 8.0 g/cm ³ ) 133.6 parts by mass.
Varnish-like resin composition 11 was prepared in the same manner as in Example 2 except for the above matters.

<Comparative Example 3: Preparation of varnish-like resin composition 13>
In Example 2, Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel Corporation, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm, true density 8.0 g/cm ³ ) 133.6 parts by mass, Fe-Ni-Mo alloy magnetic powder (Mitsubishi Steel Corporation "AKT-78Ni-5Mo", 17% Fe, 78% Ni, 5% Mo) The alloy had an average particle diameter (D ₅₀ ) of 5 μm, a true density of 8.9 g/cm ³ ), and 133.6 parts by mass.
Varnish-like resin composition 12 was prepared in the same manner as in Example 2 except for the above matters.

<Comparative Example 4: Preparation of varnish-like resin composition 14>
In Example 2,
1) Fe-Ni-Si-Cr alloy magnetic powder (“AKT-PB-1Si-3Cr” manufactured by Mitsubishi Steel, alloy of 50% Fe, 4% Ni, 1% Si, 3% Cr, average particle size (D ₅₀ ) 5 μm , true density 8.0 g/cm ³ ), 133.6 parts by mass of Fe-Si-Cr alloy magnetic powder ("AW2-08PF3F" manufactured by Epson Atomics, Fe-Si-Cr alloy, average particle size ( D ₅₀ ) 3.5 μm, true density 7.0 g/cm ³ ) 100.0 parts by mass,
2) The amount of magnetic powder (“MZ03S” manufactured by Powder Tech, Mn-Zn ferrite powder, average particle diameter (D ₅₀ ) 0.5 μm, true density 5.1 g/cm ³ ) was 40.0 parts by mass. The amount was changed from 51.4 parts by mass.
Varnish-like resin composition 13 was prepared in the same manner as in Example 2 except for the above matters.

<Manufacture of resin sheets>
A PET film ("Lumirror R80", manufactured by Toray Industries, Ltd., thickness 38 μm, softening point 130° C.) that had been subjected to mold release treatment with an alkyd resin mold release agent ("AL-5" manufactured by Lintec Corporation) was prepared as a support. The varnish-like resin compositions (resin varnish) prepared in Examples and Comparative Examples were applied onto a support using a die coater so that the thickness of the resin composition layer after drying was 70 μm, and the coating was applied at 90°C. It was dried for 5 minutes to obtain a resin sheet.

<Manufacture of sheet-shaped cured body>
The resin sheet was cut into 200 mm square pieces. The cut resin sheet (200 mm square) was processed using a batch-type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nikko Materials), so that the resin composition layer was made of polyimide film ("CVP700" manufactured by Ube Industries, Ltd.). The film was laminated onto one side of a polyimide film so as to be in contact with the center of the smooth surface of "Upilex 25S" (25 μm thick, 240 mm square). Lamination was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then press-bonding at 100° C. and a pressure of 0.74 MPa for 30 seconds. As a result, a multilayer film having a layer structure of support/resin composition layer/polyimide film was obtained.

After peeling off the support, the resin composition layer was thermally cured by heating at 190° C. for 90 minutes. Thereafter, the polyimide film was peeled off to obtain a sheet-shaped cured body of the resin composition.

<Measurement of relative magnetic permeability and loss coefficient>
The obtained sheet-like cured body was cut to obtain a doughnut-shaped evaluation sample having an outer diameter of 19.2 mm and an inner diameter of 8.2 mm. The relative magnetic permeability (μ') and loss coefficient (tanδ) of this evaluation sample were measured using a magnetic material test fixture "16454A" manufactured by Keysight and an impedance analyzer "E4991B" manufactured by Keysight at a measurement frequency of 20 MHz and a room temperature of 23°C. Measured at The loss coefficient tan δ was calculated using the following formula “tan δ=μ''/μ'.

The evaluation criteria for relative magnetic permeability are as follows.
"〇": Relative magnetic permeability is 23 or more.
"×": Relative magnetic permeability is less than 23.

The evaluation criteria for the loss coefficient are as follows.
"〇": Loss coefficient is 0.05 or less.
"×": Loss coefficient exceeds 0.05.

<Evaluation of melt viscosity>
After peeling off the resin sheet support, the resin composition layer was compressed using a mold to produce measurement pellets (diameter 18 mm, 3.5 g to 3.7 g). Thereafter, the minimum melt viscosity of this measurement pellet was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM). Specifically, for 1 g of pellets for measurement, using a parallel plate with a diameter of 18 mm, the dynamic viscoelastic modulus was measured by increasing the temperature in the temperature range from 60°C to 200°C, and the minimum melt viscosity ( poise) was calculated. The measurement conditions were a temperature increase rate of 5° C./min, a measurement temperature interval of 2.5° C., a vibration frequency of 1 Hz, and a strain of 1 degree. The evaluation criteria for melt viscosity are as follows.
“〇”: Melt viscosity is 30,000 poise or less.
"x": Melt viscosity exceeds 30,000 poise.

＊（Ａ）成分及び（Ｃ）成分の合計量（質量％）は、樹脂組成物中の不揮発成分１００質量％に対する含有量を表し、（Ａ）成分及び（Ｃ）成分の合計量（体積％）は、樹脂組成物中の不揮発成分１００体積％に対する含有量を表す。

*The total amount (mass%) of the (A) component and (C) component represents the content based on 100 mass% of the nonvolatile components in the resin composition, and the total amount (volume%) of the (A) component and (C) component. ) represents the content based on 100% by volume of nonvolatile components in the resin composition.

In Examples 1 to 9, it has been confirmed that even when components (C) to (G) are not contained, the results are similar to those of the above examples, although there are differences in degree.

1 Circuit board 10 Core board 11 Support substrate 12 Metal layer 13 Metal layer 14 Through hole 20 Plating layer 21 Surface around polished surface 30 Cured product 30a Resin composition 31 Surface of polished cured product (polished surface)
40 conductor layer 41 pattern conductor layer 100 circuit board 200 inner layer board 200a first main surface 200b second main surface 220 through hole 220a wiring in through hole 240 external terminal 310 resin sheet 320 first cured material layer 320a resin composition layer 330 support Body 360 Via hole 360a Wiring in via hole 400 Coiled conductive structure 420 First conductor layer 420a Land 440 Second conductor layer

Claims (22)

A resin composition comprising (A) Fe-Ni-Si-Cr alloy magnetic powder and (B) a thermosetting resin,
A resin composition in which the content of Cr contained in component (A) is 0.1% by mass or more and 6% by mass or less based on 100% by mass of component (A). The resin composition according to claim 1, further comprising (C) a magnetic powder other than the Fe-Ni-Si-Cr alloy magnetic powder. 3. The resin composition according to claim 2, wherein component (C) contains ferrite magnetic powder. 3. The resin composition according to claim 2, wherein component (C) contains ferrite magnetic powder containing at least one element selected from the group consisting of Mn, Zn, Ni, and Cu. The resin composition according to claim 2, wherein component (C) has a smaller average particle size than component (A). The resin composition according to claim 1, wherein component (B) comprises (B-1) an epoxy resin. The resin composition according to claim 1, wherein component (B) contains (B-2) a curing agent. The resin composition according to claim 1, further comprising (E) a dispersant. The resin composition according to claim 1, further comprising (F) a curing accelerator. The resin composition according to claim 1, wherein the content of Si contained in component (A) is 0.2% by mass or more and 5% by mass or less based on 100% by mass of component (A). The resin composition according to claim 1, wherein the content of Cr contained in component (A) is 0.5% by mass or more and 6% by mass or less based on 100% by mass of component (A). The resin composition according to claim 1, wherein the amount of component (A) is 40% by mass or more based on 100% by mass of nonvolatile components in the resin composition. The resin composition according to claim 1, wherein the amount of component (A) is 30% by volume or more based on 100% by volume of nonvolatile components in the resin composition. The resin composition according to claim 2, wherein the total amount of component (A) and component (C) is 70% by mass or more based on 100% by mass of nonvolatile components in the resin composition. The resin composition according to claim 2, wherein the total amount of component (A) and component (C) is 50% by volume or more based on 100% by volume of nonvolatile components in the resin composition. The resin composition according to claim 1, which is used for hole filling. A cured product of the resin composition according to any one of claims 1 to 16. A magnetic paste comprising the resin composition according to any one of claims 1 to 16. comprising a support and a resin composition layer provided on the support,
A resin sheet, wherein the resin composition layer contains the resin composition according to any one of claims 1 to 16. A circuit board comprising a substrate having a hole, and a cured product of the resin composition according to any one of claims 1 to 16 filled in the hole. A circuit board comprising a cured product layer containing a cured product of the resin composition according to any one of claims 1 to 16. An inductor board comprising the circuit board according to claim 20.

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